Ghostly fans

Do you believe in ghosts? No, oddly enough. I do believe in certain things that can make you feel a bit spooky. There was a brilliant programme on the other day actually, about the noise of a fan in this one office. Because it was sub-sonic and vibrated at a certain frequency, it made your eyeballs vibrate, which meant that you saw things that weren't there.

I thought that was the best explanation for ghosts - the fact that it's sub-sonic noise, and every time you walk somewhere that's a bit spooky it's actually a noise that you can't really hear, but it's vibrating things in your head which make you a bit spooked. It was some Carol Vorderman thing - the Truth About Ghosts or When Ghosts Go Bad.