People have wondered about the existence of ghosts throughout man's history. A ghost is an apparition of a dead person that may be visible to the living. Traditionally ghosts are seen as spirits stuck between this realm and the next, often as a result of tragedy or trauma. Many ghost hunters and psychics believe that such spirits don't know they are dead; they exist in a kind of limbo in which they haunt the scenes of their death or visit locations that were important to them in life. Ghosts have been reported all over the world.