In traditional belief, a ghost is the soul or spirit of a deceased person or animal that can appear, in visible form or other manifestation, to the living. Descriptions of the apparition of ghosts vary widely: The mode of manifestation can range from an invisible presence to translucent or wispy shapes, to realistic, life-like visions. The deliberate attempt to contact the spirit of a deceased person is known as necromancy, or in spiritism as a séance.
The belief in manifestations of the spirits of the dead is widespread, dating back to animism or ancestor worship in pre-literate cultures. It is not known for sure whether ghosts exist or not. Many believe they do exist from claims of sightings and evidence collected from technology designed for "ghost hunting". Although many believe they are fiction, that all ghost sightings are a result of overactive imaginations, pictures of ghosts are faked, and the evidence is a result from normal household activities, such as a furnace creating a electro-magnetic field which is believed to be a common sign of a ghost. Certain religious practices—funeral rites, exorcisms, and some practices of spiritualism and ritual magic—are specifically designed to appease the spirits of the dead. Ghosts are generally described as solitary essences that haunt particular locations, objects, or people they were associated with in life, though stories of the phantom armies, ghost trains, phantom ships, and even ghost animals have also been recounted.