This very famous ghost photo was taken at Boothill Cemetery in Tombstone, Arizona by Terry Clanton, a cousin of one of the legendary Clanton Gang, who shot it out at the OK Corral with the Earps and Doc Holliday.
Terry Clanton described the photograph; "The picture was shot in black & white, because my friend wanted an old western style picture of himself dressed up in my 1880 period clothes. I know there was no other person in this photograph when I shot it, especially some guy holding a knife!".
If you look carefully at the thin person wearing a black hat in the background, he looks as if he is holding a knife. The person appears to have no legs or as if it is coming out of a grave.