In Havana, the ghost of Ernest Hemingway has been terrifying the employees at the writer's former estate. In Madrid, a ghost named "Ataulfo" has been haunting the museun that houses Picasso's masterpiece, Guernica. In Washington, D.C., the vice president's daughter was so scared by a ghost's visitation that she fainted. Ghost sightings happen every day throughout the world. Those who have never seen a ghost tend not to believe...