Ghosts are spirits of (generally) the dead who remain earthbound and may be perceived by humans. Ghosts are normally in Spirit form, and may be visible only to those who are psychic. Spirits may communicate via mediums (> Spiritualism) or may manifest themselves in physical form, drawing either upon the spirit substance, ectoplasm, or on the energies of others present (which usually results in a sense of coldness). Ghosts may attach themselves to surroundings known to them in life, mostly commonly Haunted Dwellings; but they may equally attach themselves to other objects or people. This attachment may become sufficiently strong that the spirit takes the body over (> Possession).
Ghosts may be manifestations of other spirits, especially Demons. Ghosts may prey more on the mind and become a psychological manifestation which causes Illusion, if the Haunting is real, or Delusion if wholly psychological.
Ghosts may also be spirits of the living, perceived as a result of astral projection (> Astral Body). They may even be a projection of one's own spirit, or the spirit of one's Double (> Doppelgängers), who often come as a warning of impending doom. Animal ghosts are common in Folklore and particularly in tribal Mythology (>>> Totems). [MA]