Until she was 26, former Blue Peter presenter Yvette Fielding didn’t believe in the afterlife. But that all changed the night she awoke to find an eerie figure ­standing at the end of the bed in her mother’s house. She tells me: “I awoke in the middle of the night to discover a young, Second World War soldier staring straight at me from the foot of the bed. It was petrifying.”

Even more terrifyingly, rather than being vaporous, the youthful figure – dressed in a brown military uniform with brass buttons, and sporting Brylcreemed hair and a sharp side parting – appeared to have formand substance.

“I burst into tears and ran screaming from the bedroom into my mum’s room,” Yvette, now 55, recalls.

“Imagine, as a young woman, awaking to discover a man in your room. But although it was like looking at a solid object, he was only there from the waist up – his top half was hovering. I was sobbing, ‘There’s a ghost in the house’.”

The experience was destined to change the shape of Yvette’s life – revealing a new direction in her broadcasting career that continues to this day, as well as helping introduce her to her second husband, TV producer Karl Beattie. Most Haunted, the paranormal research series presented by Yvette and a gang of experts, and produced by Karl, is now filming its 26th season.

Yvette explains that her compulsion for the paranormal turned from terror into fascination following a grim discovery made after her haunting experience.

“Mum and I felt compelled to research the young man in uniform,” she tells me. They started by talking to the neighbours. “There were only five houses in the road, and we discovered that a couple of them had seen exactly the same thing,”she explains.

Things then became even stranger still when they dug deeper and spoke to anolder resident.

“Behind the houses was a wood, and beyond that, the Manchester to London ­railway line.

“I spoke to a neighbour who said that during the war, the young soldiers were sent south by railway to fight, but one young conscript had thrown himself off the train as he didn’t want to go, and was cut in half by the train.”

Convinced that this explained the apparition that had so alarmed her, fearturned into fascination.

“That first-hand experience has now led me on a journey that has become such a huge passion, and it has actually changed my entire life,” Yvette reflects.

“Before this experience, I didn’t believe in anything. I didn’t believe in a God. I didn’t believe in life after death and those feelings affected me in a negative way because when I had the usual share of awful times, as we all do, I would wonder what life is all about, why are we here, where did we come from and is that it when you’re put in the ground at the end and it all goes black?”

Now Yvette’s latest children’s book, about haunted castles, has just been published, mining her on-camera experiences and bringing them to life in spooky fashion for a brand new audience of young readers.

And it was shortly after meeting Karl that she discovered he had also had a similar experience to her; a fact that proved to be deeply bonding.

“When I met my beautiful husband, he had had his own haunted experiences,” she tells me.

Karl takes over the tale: “One night, when I was about 10 and my brother was five, I saw a man wearing a fedora hat and dressed in a 1930s costume, leaning on my bedroom door frame.”

As with Yvette’s visitor, he was similarly solid but faded over the next few minutes.

Says Karl: “I thought I may have dreamed it, but it was only in the morning when we got up for breakfast that my little brother said that he had got really scared in the night because there was a man leaning on the wall in a Humphrey Bogart outfit. He was so young that this detail made me think there had to be some truth to what we had both seen.”

When the couple, who have been married for 25 years and have a daughter, Mary, met on the set of BBC One’s documentary series City Hospital, they soon found themselves sharing their experiences.

Says Karl: “Yvette and I connected on so many levels when we met, and had this sense that we had met each other before and when I talked about this experience, she took me seriously. We were both used to people being sceptical.”

Yvette, who also has a son, Will, from a previous marriage, says that this led them to become ­increasingly intrigued to the point that they came up with the idea for the TV series. Sheadds: “We were so passionate about the topic that we spent all our life savings making the pilot and for a while we couldn’t pay the mortgage.”

Worryingly, all the mainstream TV ­stations turned it down.

“Channel 5 even called us ‘unprofessional’ for delving into this genre,” she recalls. “But something in us kept pushing until the satellite station UK Living said yes.” At the time, the station was losing viewers, but the couple were told “this might be just mad enough to work”.

Sixteen initial episodes were commissioned, and Yvette found herself launched professionally into the world of the paranormal. “We don’t know all the answers and the only experts are those who have passed on,” she says now. “But I definitely call myself a paranormal researcher.”

And as she gazes into the camera, often in the eerie black and white world created by heat-seeking night vision cameras, she says she never forgets the advice she was given as a 19-year-old presenting rookie by Biddy Baxter, the legendary Blue Peter producer. “One thing Biddy always said was that it is so important just to be yourself as a presenter. She said, ‘Never, ever when you look in the camera, think of a lot of people. Just think of one, your best friend, and you are trying to talk to them’.”

It’s advice she continues to heed. “I think it’s really important for presenters to remember that. Audiences are not daft, they know who a genuine person is.”

Biddy first saw Yvette on TV at the age of 13, acting in the BBC Children’s TV drama series Seaview, and became determined to recruit her to the flagship teatime show.

“Maybe she liked the Kevin Keegan-style perm I wore for my part,” laughs Yvette when I ask why.

“She waited until I was 16 and invited me for an audition, but decided I was too young at 16 and Caron Keating got the job instead. Then I got a phone call just before my birthday asking if I would come back the following year.”

This time, Yvette was successful and, in 1987, she appeared on the show for the first time at the age of 18. “It was absolutely incredible to get a job as a Blue Peter presenter, both terrifying and exhilarating, as you get to travel the world,” she continues.

“I would never otherwise have gone to Russia or the west coast of the US, be trained to fly a Sea King helicopter or have the chance to go down a bobsleigh run.”

Yvette is convinced Biddy chose her for the covetable role due to her senseof humour.

“When something went wrong, I couldn’t stop laughing, like when I couldn’t get on a trampoline in my audition and, when I did, I looked like a huge pumpkin bouncing up and down. Mark Curry [the Blue Peter presenter] told me he and Caron were watching my audition and found it hilarious.”

Now as Yvette takes the viewer with her into haunted castles and houses on Pluto TV, she still manages to be playful. Until, that is, something sinister happens.

This reached a head when she resigned live on air while filming at Edinburgh Vaults in 2006, following a truly alarming experience involving injuries to her production colleagues.

“I was filming Most Haunted Live on the Discovery Channel, and broadcasting simultaneously in both the US and UK, when I saw, for the first time, scratches and cuts appearing on crew members. I was really perplexed, because it had always been my understanding that ghosts can’t hurt you. I couldn’t stop crying, it was so upsetting, and I was trying to hold it together.”

She walked away from the broadcast when a sound engineer collapsed with a deep laceration to his leg.

“He was taken to A&E, and to me that was enough. I wanted to catch a ghost, but I was scared.”

It was the fans who persuaded her to return a few months later.

“They said, ‘Please don’t resign’, and I decided to turn fear into research,” she says.

As she examined the literature on violent poltergeist occurrences, she says she realised there was so much more to learn in this rich and disturbing area.

“There are examples of people being cut, bruised and burned. It really opened my eyes and I realised we have not even scratched the surface of this world. I said, ‘Come on Fielding, let’s look into this’.

“Now I’m so intrigued – if someone says they have a scratch, I’m rushing over there. I’ve gone all the way from terror, through intrigue, and back to wonder,” she says.

Most Haunted Castles by Yvette Fielding (Andersen, £7.99) is out now. Visit expressbookshop.com or call Express Bookshop on 020 3176 3832. Free UK P&P on orders over £25.