Both the lollypop lady and the baker on his delivery round saw it from the street — visible through a bedroom window was an 11-year-old girl, floating, it seemed, in mid-air. The story of the Enfield Poltergeist has continued to intrigue ghost-hunters since the first reports some 30 years ago of a single mother and her children being afflicted by apparently unexplained phenomena in their north London council house.

A key figure in the case was a former warden of Muswell Hill Synagogue, Maurice Grosse, who investigated it on behalf of the Society of Psychical Research and remained convinced up to his death in 2006 that it was genuinely paranormal. But another Jewish character was also involved — the medium Gerry Sherrick.

The East End-born cab driver, who turns 75 this month, is now in frail health. He contacted the JC after our report a few weeks ago of ghostly goings-on in a synagogue — coincidentally in Enfield — where a former minister was supposedly so attached to his congregation that his spirit still hung around the place.

He lives in a little flat in a Jewish Blind and Disabled-run block in South Woodford, Essex with his wife Lauretta. He was brought to the Enfield poltergeist case by another paranormally-inclined Jew, Maurice Barbanel, the editor of Psychic News, who introduced him to the other main investigator, Guy Lion Playfair (and author of a book about it, This House is Haunted).

“We went round to the house in Enfield,” he said. “The family were very distraught, and they were having terrible difficulty because they were constantly aware that somebody was in the home, furniture was being shifted, they could hear the sounds of people crying, making noises.”

Believing he could help, he asked the family if they were aware of the smell of rotting fruit. When the mother, Mrs Harper, replied yes, he told them: “I have to tell you, without you being afraid, who is causing this trouble. There is a very ugly old woman standing here and she has attached herself to the children. She is telling me, ‘P-i-double-s off, you’re not wanted, get out, get out’, and I had to explain to her that she wasn’t wanted there any more but she was still persistent.”

They managed to clear the home of its unwanted visitor. But he added: “Children do draw entities back. For a time everything was perfect until one of the girls again tuned her mind into it and drew something back.”

Sherrick’s psychic gift, he believes, is inherited — his mother Clare was a medium, while his father lectured on reincarnation. But he did not become aware of it until he was nine or 10.

“I had twin sisters and one was killed in a road accident so I really never knew her,” he said. “At the foot of the bed I used to keep my bicycle which my parents had bought me. I woke in the middle of the night with the light from the bicycle shining down towards the foot of my bed and there I saw a young girl of about five or six. She smiled at me and she said, ‘Do you know who I am?’

“I said, ‘I am not sure’. She said, ‘I am your sister Rebecca and I have come to see you.’ I was so frightened I got under the blankets and my mother had to get me out, I was terrified. I explained to my mother what I had seen. She took me by my hand and opened a cardboard box. There was a picture of a little girl — the little girl that I had seen. That was the beginning of my psychic experience.”

Starting to hear and see more things, he thought he was going mad until his father explained: “If you buy a radio, you can get a number of stations. A medium is built with another channel, a psychic channel, which is able to see those who the physical eye can’t see.”

A ghost, he said, is “not somebody who walks around with a white shawl over his head making noises as if he were constipated”. In his softly-spoken way, he related some of his encounters: the Roman soldier murdered by druids at the bottom of a cave in Kent; the Belsen guard raging against Jews at a mediums’ circle; the young John Keats appearing under a tree in his eponymous Hampstead grove.

“I don’t make people believe, but I believe,” he said: “You’ve got to see it with your own eyes.”

But the most disturbing story he tells does not involve the paranormal. “I studied psychoanalysis and one of the conditions called lycanthropy [a delusion that someone has turned in to an animal]. It must have been 11 o’clock one evening when the phone went.” The caller was a woman desperate for help. She was from the Caribbean and her niece had come from one of the islands to stay.

“She told me: ‘One evening my niece came home very agitated. She said, Auntie, if you love me, please lock me in my room.’ The aunt locked the door.

“She said, ‘Mr Sherrick, I woke up in the night, someone was clawing at the wallpaper, it was like an animal at the wallpaper. She said I was terrified, I got out of bed, I tried the lock on my niece’s door but there was no answer. I got my rosary and I sat there all night praying to my Lord.

“‘The next morning I opened the door. The door was covered in excrement and my niece was laying on the floor, doubled up naked.’ Then the woman said, ‘I’ve got to stop, she’s coming in,’ and she banged the phone down.”

Later he worked out that the niece must have been going out with a boy in the village where she lived. When the boy learned she was going away to England, he went to a voodoo woman. The woman put the thought in her mind, without her knowing it, that at a certain time, on a certain day, this would happen to her. It’s a form of insanity.”

To grieving relatives, he has brought the comfort of his conviction that there is “life after life… To me, death is an outdated word. Just as a relative or friend may emigrate to a distant country, so there must come a time when we must leave our physical body and pass into the spirit world.”

If a medium can give people “proof of survival and take away some sorrow, I can do as much as a rabbi can”.

He has never taken a penny for his spiritual service, he said. “A gift given freely should be given freely.”

But for all Sherrick’s belief in the supernatural, religiously he is agnostic, though he says he loves his Judaism.

At one point, he asks if I can feel the room getting colder. I don’t think I can, but he tells me that he can feel someone standing behind me, his hand over my head. “If you feel a coldness around your head, it is the gentleman from the spirit world. He’s mentioning names — do you know Sidney or Sid, there’s a Harry, Hirschel, two people who have come to you from the spirit world.”

As with many Jews of my generation, there are a few Sids in the family locker and I was nicknamed after one at school. Sherrick has a message for me from the spirit gentleman — but nothing to shake a sceptic’s faith in his scepticism.

Before any more astral communiqués can be delivered, however, Lauretta commands: “Gerry Sherrick, turn off!”

Before I go, he reads me a rather sweet poem about a zeide — he still writes verse and has read his poems on radio and TV. Then he gives me a blessing, asking me to close my eyes and takes my hands. The effect is uplifting, a melting-away of tension as if I had just had a massage. Buoyed by a sense of wellbeing, I leave, remembering his appeal: “We don’t ask you to believe it, we don’t ask you to accept it — keep an open mind.”