The Ghost of Cam Ranh Bay Air Base:

According to the story, an Air Policeman was found dead on the South China Sea area of Cam Ranh Bay AB with his right hand cut off and missing.  The remaining hand was discovered pointing out at the sea.  The story goes that when pulling guard duty in that area, several security police have been startled by the hand tapping them on the shoulder. 
    A new in country SP was told the story by a veteran and sometime later was heard screaming on the radio to be relieved from his post.  I don't know if the story was true (probably not) but it sure was great fun to use on the new guys.