If you've ever thought a bump in the night was the sound of your long-gone grandmother haunting the attic, then you’re not alone. According to an ICM survey for UKTV, 42% of us now think ghosts exist, compared with only a third of people in 1954.

And there’s no shortage of folk willing to go public about their ghostly experiences. In Joanna Lumley’s autobiography No Room for Secrets she claims to have had multiple supernatural encounters, including one with a man who warned her to leave an old house in Kent just as she was moving in.

Kylie Minogue claims she has been “visited” by Michael Hutchence, a former lover, who died in 1997. And Russell Grant, the astrologer, has talked of being visited by Princess Diana in a dream and feeling “clear signs she wanted to make contact with me”.

“The enthusiasm for things like ghosts, horoscopes, angels and pixies reflects a pre-Enlightenment cast of mind,” says Francis Wheen, author of How Mumbo-Jumbo Conquered the World: A Short History of Modern Delusion. “It does seem odd that the extraordinary technological and scientific developments have been accompanied by an epidemic of superstition and anti and pseudo-science.”

Groups of paranormal enthusiasts are emerging all over the country. For example, a West Midlands group of ghost researchers called Parasearch now counts university staff, police, care workers and even a nuclear physicist among its 25 members.

“These things come in cultural fashions,” says David Taylor, the chairman of Parasearch. “First it was crop circles, then UFOs following television programmes such as The X Files and now it’s ghosts because of programmes about haunted houses.”

At Living TV, for example, ratings for the Most Haunted series have increased fivefold to 1m viewers in two years — not counting the Most Haunted Live! show, which was watched by 2.7m viewers during Hallowe’en.

But while television shows on the paranormal offer late night entertainment can the investigation of ghosts ever be taken seriously?

In 2003 Professor Richard Wiseman of Hertfordshire University revealed his investigations into paranormal experiences in the British Journal of Psychology, the first time a peer-reviewed scientific journal had published such a paper. His research team had organised more than 450 people to walk round haunted sites — including Hampton Court, Henry VIII’s old palace, supposedly haunted by Catherine Howard, the king’s fifth wife, who was executed in 1542.

Wiseman concluded that people genuinely experience something but these feelings are the result of physical phenomena such as poor lighting and magnetic fields exciting the senses. That means it wasn’t a poltergeist tickling your neck, probably a freak draught caused by bad insulation.

“I don’t think all apparitions are just creations of the mind,” argues Bernard Carr, professor of mathematics and astronomy at Queen Mary University of London, and vice-president of the Society for Psychical Research. “For example, there are collective cases where several people see the same apparition at the same or different times. There are also cases where the apparition conveys information that was unknown at the time but subsequently verified. Although we don’t fully understand these phenomena, scientists should investigate them.”

There is already growing academic interest. Ten students are studying for PhDs in parapsychology at the Koestler Parapsychology Unit at Edinburgh University. One research fellow at the unit has been awarded a grant of £54,000 to investigate magic.

But groups that attempt to apply science to the study of the paranormal are outnumbered by groups set up by enthusiasts looking for eerie sightings. Ian Addicoat, 32, runs Haunted Cornwall organising visits to castles and manor houses. This year 40 weekends are full — pulling in about 20 people for every evening visit.

“It’s a mixture of regulars and new people,” he says. “We’ve even had a couple come on a haunted walk as part of their honeymoon.”

That a fascination with the paranormal has risen as there has been a decline in support for traditional religion is of no surprise to Philip Corr, a psychologist at the University of Wales Swansea. He says it is part of our survival instinct.

“Psychologically, the death of others is a highly emotionally, challenging experience,” he says.

“The belief in ghosts and religion in general may well have a strong Darwinian basis in natural selection. Individuals who had coping strategies, albeit irrational ones such as believing in the existence of spirits, might have been better able to deal with these negative health consequences.

“So we should not be surprised to find the widespread acceptance of such beliefs that protect us against the realisation that death is inevitable and final.”

But for Bill Durodie, director of the International Centre for Security Analysis at King’s College London and an expert on the study of risk, the rise of irrationality and the belief in the paranormal is the result of a breakdown in social networks leading to a profound mistrust in all sources of authority.

“It’s not surprising that people fetishise perceptions,” says Durodie. “When even scientists such as Sir William Stewart, chairman of the government inquiry into mobile phones, suggest that ‘anecdotal evidence should be taken in to account’, it feeds an explosion of actions in society done on the basis of myths, hearsay, rumour and superstition.”

Of course, believers in ghosts can always ask non-believers for proof that ghosts don’t exist. But nobody can prove a negative.