It's claimed the dead have found a new way of contacting the living.
Not by rapping on tables or spewing ectoplasm over a twitching medium, but via electronic signals.
So-called "Electronic Voice Phenomena" (EVP) are supposed to be the voices of ghosts, made audible through static on the radio, or on tape recordings.
Linda Williamson believes she has heard from beyond the grave
It sounds like the plot of a Hollywood movie - Ghost crossed with The Cable Guy perhaps. And in fact it is.
Michael Keaton's new film, White Noise, features a murdered woman who identifies her killer by speaking onto a tape machine.
But there are people who say Electronic Voice Phenomena aren't fiction but fact.
Linda Williamson from Dundee is one of them.
She used to work as a cleaner in a now demolished factory. It was supposed to be haunted, so out of curiosity she left a tape machine running in a deserted room while she and a colleague worked at the other end of the building.
'Talking and laughing'
It was very early and no-one else was there, so she was astonished when she played the tape back and seemed to hear several people talking, some laughing and lots of banging noises.
Since then she's made hundreds of recordings which, she says, feature the voices of a range of dead people - from celebrities to relatives and family friends and even barking from a deceased dog.
Many of her tapes, she says, include messages from beyond the grave. "They're asking for help, or they're coming over and saying 'I love you'," she says.
Linda has always been fascinated by why someone who's died would choose to leave an electronic message on a tape machine. "Maybe," she speculates, "it's the fact that man's technology has improved so much that means they're able to do that."
Some of the recordings only become audible when they're slowed down or even played backwards.
She understands that some sceptics will accuse her of doing whatever it takes to manipulate tapes until messages she - or others - are desperate to hear somehow appear.
But she says she's recognised the voices of family members - including her mother. For her, "that's proof that my own family members who have died still go on in some form".
Here's the science
Professor Chris French, from the Psychology Department at Goldsmiths College, University of London, isn't convinced.
He says some of the alleged EVP recordings come from leaving a microphone and tape machine in a place that's supposed to be haunted.
"In that case," he says, "there's the possibility that you might pick up real voices from real living human beings that happen to be walking nearby. People want to believe."
Linda keeps her recordings on her PC
Other tapes emerge from static, or untuned radios. He says those can be explained as voices from other broadcasters being picked up as transient radio signals.
But he says the common thread behind all the examples he's heard is that people are "reading meaning into what's actually random noise".
"For obvious reasons, people want to believe there's an afterlife and that means the evidence doesn't need to be very good for people to be convinced by it," Professor French added.