Hayley Stevens is that rare thing, a sceptical ghosthunter. Where others go into “haunted” houses with infrared cameras and a jumpy disposition, Stevens prefers to take an open mind and a notebook.

It wasn’t always so; her interest in the paranormal began in the rather more traditional manner of the believer, messing about with Ouija boards and glasses in an attempt to communicate with the beyond.

At 18, she formed a paranormal investigation team in her home county of Wiltshire: “We’d go out looking for ghosts and when you look, psychology tends to dictate you find them.”

But things got a little shaky when a number of self-styled TV psychics were exposed as having cheated in their practice. Then Stevens and her team went to an allegedly haunted pub where they uncovered the landlord playing poltergeist in the hope of drumming up business.

“We caught him hiding behind the door throwing things across the room,”

she recalls. “It was all rather embarrassing.”

She started to question her belief and began looking into the science and psychology of paranormal investigation, when she found out about logical explanations for seemingly spooky activity – the ideomotor response, for example, the often involuntary but solely human movement of glasses used in “divination”, and the “101 logical explanations” for electronic voice phenomena, where people believe they have captured the voices of spirits.

Now, the 25-year-old carries out her investigations in a cooler fashion. She will go to a site alleged to be haunted and spend time chatting to locals, researching the building and its history and attempting to disprove various theories.

Some are easily cleared up; a supposedly ghostly figure sighted on Clevedon Pier in North Somerset turned out to be a local fisherman, who recognised himself immediately due to his red flotation jacket. Others are harder to get to the bottom of.

She is still investigating “Bownessie”, the monster alleged to lurk in Lake Windermere in Cumbria. While she has been able to rule out certain theories – some thought it was two cat fish who had “mysteriously” disappeared from the local aquarium, which Stevens found living happily in the lake of a local golf club – she has yet to find a rational explanation for the photographs and sightings.

In the next few weeks, she is set to take two tyres out into the lake to see if it is possible to hoax a monster that way, another possibility that has been suggested.

Stevens believes she takes a more sympathetic stance than many sceptics. Having grown up in a house her family thought was haunted (doors would open unexpectedly – she now thinks it was the result of air pressure fluctuations in the chimney) and having started out as a believer herself, she can understand why people are defensive when presented with evidence that contradicts their beliefs.

“I know when you invest time in a belief, to suddenly be asked to reconsider everything is a big ask and something you can only really do of your own volition. When I research a case, I’ll give people my opinion and my findings, but I don’t expect them to accept it necessarily.”

And there are things she still can’t explain, she adds.

“I did an investigation in a shopping centre when it was closed down for the evening and I saw what I can only describe as a little boy running across the shopping centre and disappearing round the corner and the people with me saw it too.

To this day I can’t explain what it was, but I wouldn’t say it’s a ghost because I don’t know what a ghost is.

“I’ve heard weird things too. In one location I heard someone whistling but there was no one there. In another, I was stood in the middle of the room and someone pulled my arm. I don’t know what it was and I am open-minded to the idea there could be ghosts, but I’m yet to be convinced.”

Most of the situations she investigates stem from genuine concern and while Stevens takes a rational approach, she does not set out to tell people they are being stupid.

“A lot of the time, people have experienced something strange and just want someone to believe them. I do believe they’ve experienced something strange, I just want to question their explanation for what that was.”

Things get muddier when there is a suggestion that vulnerable people are being misled. Stevens has filed a number of complaints to the Advertising Standards Agency about groups claiming to be able to heal cancer through the laying on of hands and the like and she founded Project Barnum, a website that outlines tricks psychics sometimes use on stage and how to spot them.

These include familiar tactics such as cold reading – the use of generic statements many people will identify with – and less well-known tricks like “shotgunning”, where someone will make random statements in the hope someone will connect with them.

“Ever since I started out, I’ve worked with people claiming to be psychics and mediums and I became aware of stage tricks they willingly or unwittingly use – sometimes people who think they’re psychic don’t realise they’re cold reading or fishing and have convinced themselves they are psychic. I didn’t want to attack individuals because I don’t think it’s the best way to get the message across, so I just inform people of the tricks that might be used so they can be wary of them and avoid being exploited.”

The gimmicks and scams sometimes used have not progressed far from the Victorian heyday of séances and spirit guides, Stevens says.

“With Victorian séances, it was a table that ghosts would supposedly communicate through, now there’s an iPhone app you can download for ghosts to communicate through.”

By day, Stevens works in arts administration – she can’t tell me where because of the number of threats she has received as a ghosthunter.

“I have to be careful about what information I put out about myself because people have tried to get me sacked. Someone tried to get me sacked because I said on my blog I didn’t think their house was haunted and someone else tried because I didn’t believe their pictures showed ghosts. It’s annoying and can be upsetting being threatened but I can understand why they do it.”

Ghosthunting is a hobby – she makes no money from it – borne out of a desire to get to the truth of a situation.

“It’s not as exciting as people think. A lot of the time I’ll just be researching for hours on the internet.

But it can be really rewarding when you discover something that means other things suddenly slot into place.”

She tries to avoid revealing what she does to strangers – a former boss dropped what he was holding when she told him she was a ghosthunter, while others are eager to tell her about an uncanny experience they once had and get her opinion on what it might have been.

She enjoys the talks she gives nationally, however, and meeting people who have often not considered the possibility of a sceptical ghosthunter. “Everyone is generally quite curious about ghosts and monsters and weird things – it’s part of our culture. Wherever I go, people always have an opinion on the subject one way or another.”

* Hayley Stevens will give her talk I’m A Ghosthunter, Get Me Out Of Here at Skeptics In The Pub at the Caroline Of Brunswick, Ditchling Road, on June 12. For tickets visit www.brighton.skepticsinthepub.org.

* For more information on Hayley Stevens, visit www.hayleyisaghost.co.uk.