Can you help solve the strange case of the haunted chair? If so, Desmond Davies would like to hear from you.

He called to tell me he's mystified by what happens overnight to the chair by his writing desk.

When he comes to sit at his trusty typewriter in the morning, he finds the chair has collapsed – and he's wondering if there could be some supernatural explanation. A mischievous poltergeist, perhaps?

Desmond, 86, of Northville, Bristol, finds one arm of the chair has come loose, and that its seat has been lowered. Each time he has to screw the arm back in place, and jack up the seat.

"I sit on the seat and it's gone down again, and the arm's gone wobbly!" said Desmond, a former technical illustrator with British Aerospace. "It doesn't bear thinking about what could be interfering with it. I can live with it, but my curiosity has been aroused."

Desmond insists that his sitting in the chair, which he obtained from British Aeospace six years ago, doesn't cause the problem, and says he'd welcome a visit from a group of paranormal investigators.

"The supernatural has crossed my mind, but nothing else like it is happening in the house," he added. "It's only that area."

As well as writing, Desmond enjoys painting pictures of aircraft and famous actors – one of his paintings, of Sir Laurence Olivier in naval uniform, hangs in the boardroom at RNAS Yeovilton, Somerset.