Ghost stories are popular
becaus they reaffirm the belief that there is some kind of life after death. That wish is so powerful that it is hard to accept that anyopne who really believes it is doing so rationally.
As for the "scary part", nothing in hell or horror can be scarier than the kind of people who kidnap young women and keep them chained up for sex for ten years. You don't need the supernatural to provide real horror. Plain ordinary people are much better at it than any spook could possibly be.