A poltergeist is a disembodied spirit or supernatural force that is credited with malicious or disturbing phenomena. Such phenomena include noises that cannot be explained, sudden wild movements or breakage of household items.
Poltergeists are also blamed for violent actions, such as throwing stones or setting fire to clothing and furniture. Events for which poltergeists are credited are usually occasional, unpredictable and repetitive. According to popular belief, poltergeists focus on a specific member of a family, often an adolescent, with a goal of harassment. The unusual phenomena usually cease when strangers are present. According to the Encyclopedia Britannica, a large portion of people that have been reported to be victimized by poltergeists suffer from hysteria. In many cases, the activities that are attributed to poltergeists have been explained as natural phenomena, such as the normal creaking of boards in an old house.