I didn't find anything about it in a search of the standards--no guidelines on stories at all.

I don't think we've ever officially told the staff "no, they're not allowed," but it's probably come up when talking about other things. No one really wants a crying camper. Kids get scared about weird things enough as it is... like, when we sing something in a minor key...

When I was a teenager I made up a ghost story--really, embellished something that had happened in camp history--and scared my fellow campers, but scared myself worse than anyone else.