Spooky feelings all around you? Track down their source!

Some time ago, an interesting manuscript was received at the EPE Editorial office. The author, Vic Tandy, had apparently heard that his workplace was haunted, but as a confirmed skeptic in ghostly matters had dismissed it as colleagues' imagination. Until that is, he had occasion to work late one night. Suddenly he experienced all the phenomena associated with the supposed haunting: the hair standing on the back of the neck, a feeling of being watched by another "presence", a deep sense of unease ... Some time later, quite by accident, he discovered the presence of strong sub-audio "standing waves" in the air of the affected premises. The source of these was subsequently traced to an extractor fan. Modifications were made to prevent the formation of the standing waves from this fan and the apparent "haunting" promptly ceased.

The obvious conclusion was that serious ghost hunting enthusiasts should include a test for such standing waves to the "armory'' of physical checks they already use in order to establish that the "ghost" they are investigating is not due to some simple physical effects generated on this earthly plane.

A copy of this manuscript was sent to Andy Flind, the author of this article, with a suggestion that perhaps some suitable equipment might be designed and presented for enthusiasts to construct. The result is this project.