A haunted house is a house or other building often perceived as being inhabited by disembodied spirits of the deceased who may have been former residents or were familiar with the property. Parapsychologists attribute haunting to the spirits of the dead and the effect of violent or tragic events in the building's past such as murder, accidental death, or suicide. More scientific explanations for the perception that a house is haunted include misinterpreting noises naturally present in structures, waking dreams, suggestibility, and the effect of toxic substances in environments that can cause hallucinations. In a 2005 Gallup poll, 37 percent of Americans, 28 percent of Canadians, and 40 percent of Britons expressed the belief that houses could be haunted. Fotopedia encyclopedia: images, pictures, photos, photographs for humanity.