According to superstition, some signs of a haunting include strange, inexplicable noises, a sense of being watched, recurring nightmares and pets or children behaving oddly. Such signs are likely to have more mundane explanations and may also include misplaced objects and electrical appliances seeming to turn on by themselves.
Superstitions about ghosts tend to be more associated with older houses, since these will have had more time for former owners or tenants to develop enduring attachments to them. However, it is not unheard of for new homes to be considered haunted as well.
Scientific researchers of purportedly haunted houses often ascribe so-called paranormal experiences to a combination of electromagnetic fields and infrasound — a very low-frequency noise that may be caused by wind — both of which have been linked to strange experiences and feelings. Infrasound caused by wind could also explain why alleged ghosts are often accompanied by a drop in temperature.
Skeptics suggest that superstitious people who believe they are experiencing a haunting test the supposed ghost's powers. One way to do this is to write out the letters of the alphabet on paper, cut them out individually and lay them face down, before asking the "ghost" to use them to spell out words or messages.