My great grandmother lived on top of a hill. From her front porch, you could observe this light move between two mountains in the distance (maybe 1/2 to 1 mile as the crow flies). The light would move from one mountain top to the other and back again, etc....
The light has been there since my mother was a little girl and she was born in 1927. Her father and a group of men once tried to locate the source of the light by going over to these mountains, however, when they arrived at the location where the light looked like they were located, they saw nothing (no light). However, the light was visible the entire time from the observers from a distance.
The full story is avaliable at www.ghosts.org.