For some reason many filmed western ghost stories deal with an actual mystery that must be solved. Once the mystery is solved the dread and unease disappear. Mysteries might be good, but the format does no good things to a ghost story.

"There is a lot of money tied up in this film and people expect to hear a boom when something blows up, so I'll give them a boom."

George Lucas as quoted by Harlan Ellison's WATCHING