The sceptic who went ghost hunting and found her beliefs shaken: Don't believe in life after death? Read Alice Vernon's astonishing account of what happened to her and you might change your mind...

Ghosted: A History Of Ghost Hunting, And Why We Keep Looking, by Alice Vernon (Bloomsbury Sigma £20, 304pp)

Of all the weird things that have happened when the dead manifest themselves through the living, the white ‘ectoplasm’ flowing from the mouths of early 20th-century mediums must be one of the oddest.

When Perthshire-based medium Helen Duncan conducted her seances in the 1920s and 1930s, her enthralled audiences were convinced that the spirits of the dead were really speaking through her.

A stout middle-aged woman in a voluminous black gown, Duncan sat in a darkened room in a trance, ‘materialising’ spirits through long, white emissions that drooled from her mouth. In photographs, they now look like unspooled lengths of lavatory roll or NHS bandages.

The renowned psychical investigator Harry Price was intrigued. He requested that she conduct some test seances in laboratory conditions, so he could examine the ectoplasm close at hand. He was convinced she was hiding whatever it was made of inside her clothing or one of her orifices.

Helen submitted to the tests, but when a doctor tried to X-ray her, she reacted violently, hitting her husband Henry across the face, almost hitting the doctor who dodged just in time, rushing out onto the street, screaming her head off, and tearing her seance garment.

The men managed to coax her back into the lab, scissors ready for when the ectoplasm started frothing from her mouth again. They managed to snip a little piece off, and it turned out to be made of paper soaked in egg-white, which she’d kept in her mouth rolled up into tiny balls.

In 1944 she would be the last person in Britain to be imprisoned under the Witchcraft Act, which made the fraudulent summoning of spirits illegal.

As Alice Vernon writes in her lively, highly readable book about the history of ghost hunting and its continuing wide appeal, expectation plays a large part in whether you do or don’t see ghosts.

If you believe in them, you’ll be more likely to see them. This was proved in the ‘Philip Experiment’ of 1972, in which a group of Canadian psychical researchers invented a fictional 17th-century aristocrat called ‘Philip’. They created a whole life story for him, including that his cuckolded wife Dorothea had his raven-haired gypsy lover executed for witchcraft, and that Philip then threw himself off the battlements of his manor house.

Amazingly, with the help of songs, prayer, and palms flat on the seance table surface, the group did manage to summon Philip’s spirit from the dead, even though he’d never existed. The table started to shudder and glide across the carpeted floor, and when they asked ‘Philip’ about his murderous wife Dorothea, they were met with ‘animalistic scratching sounds beneath the table’.

Vernon deduces that the role of expectation is potentially the key to many ghostly experiences.

A natural sceptic herself, she admits to experiencing this disarming phenomenon twice during her research for this book.

First, she went on an ASSAP (Association for the Scientific Study of Anomalous Phenomena) training course in the Old Prison at Northleach in the Cotswolds. Participants were asked to spend time alone in different cells and record their feelings.

In one cell, Vernon felt particularly icy cold; in another she felt lonely. She also went back to the police station attached to that same prison, put on headphones connected to a radio-like ‘spirit box’ designed to pick up frequencies from beyond the grave, and suddenly heard an angry man bellowing ‘No! No! No! No! No!’ into her ears. She whipped off the headphones, genuinely terrified - and, as she admits, slightly less sceptical.

Both ghosts themselves, and the kit to investigate them, have kept up impressively with changing technology. Ghosts have evolved from waifs in white roaming oak staircases of manor houses, to voices ‘writing’ through mediums after the loss of life in the First World War (bringing consolation to grieving parents).

There have been audible voices picked up on cassette tapes, post-war poltergeists throwing cats’ beds across suburban sitting rooms and (nowadays) voices of the deceased speaking through AI.

You can download an app that detects fluctuations in the electromagnetic field, and emits written phrases like, ‘I died here’, ‘drowned’, ‘many of us’, and ‘1800s’.

A typical ghost-investigating kit used to consist of Victorian items such as phials of powders, clumps of wool, a tape measure, sealing wax, compasses and balls of thread, and in the mid-20th century lightbulbs, electric bells and a telephone, but today’s ghost-hunter wouldn’t leave home without a Rem Pod (a special device for detecting changes in electromagnetic fields and temperature).

They’d also have a spirit box to scan radio frequencies which can supposedly be manipulated by spirits, plus a few ‘trigger’ objects designed to appeal to a broad range of ghosts, such as a teddy bear that lights up when a spirit comes near.

The craze for ghost-hunting tourism started booming when the TV programme Most Haunted was broadcast in the early 2000s, and it’s still going strong. ‘You too can be whacked in the face by “Fred” for £400 per four-person group for a 14-hour experience,’ Vernon writes.

‘Fred’ is the poltergeist who haunts 30 East Drive, Pontefract, a council house now owned by the film producer Bill Bungay, who insists that any footage taken in the house is his copyrighted property.

Sceptical though she is, Vernon is moved by true stories of how grieving parents were deeply consoled by the certainty that, via mediums, they could keep in touch with their sons who’d been killed tragically young in the First World War.

Oliver Lodge’s son Raymond was killed in 1915. Raymond and his wife started having seances with a medium called Gladys Leonard, who ‘channelled’ Raymond. ‘Now we can face Christmas,’ Raymond’s mother said. Raymond described his life beyond the grave in a benign socialist utopia version of Heaven, where he even enjoyed his daily cigar.

Lodge’s book, Raymond; Or, Life And Death, ran to numerous editions and sparked a new genre of books ‘by’ young men who’d died in the trenches. Though she laughs at the accounts of how conjurors such as Harry Houdini ruthlessly exposed fraudulent mediums, by showing that he too could play tricks just like theirs on gullible audiences (‘it takes a conjuror to spot a conjuror’), Vernon admits that it’s impossible to prove definitively that ghosts don’t exist.

After meeting today’s committed ghost-hunters, who are mostly delightful, ‘I found my disbelief shakier than it was’.