Yesterday was Halloween, which is usually associated with supernatural elements.
Thinking about ghost stories and storytelling, I want to talk about why some stories are more believable than others.
Except for the fantasy genre, the general rule is that readers/audience will accept ONE fantastical element in their story.
The Time Traveler's Wife has one element - Henry's time-traveling ability. If the protagonist is also a vampire or his wife, Claire, also has another magical ability, it would be extremely difficult for the readers/audience to accept it. Everything else in the story, except for Henry's time-traveling ability, must be believable. His love for Claire and his interactions with people are believable and ground the story in reality, even though he can travel through time.
Readers are generally willing to suspense their disbelief if the story is good enough and you don't require them to suspense their disbelief too much.
But, how much is too much?
More than one is already too much.
Memento has one major leap of faith - the protagonist, Leonard, suffers from anterograde amnesia. It's a major leap because it's extremely uncommon. Everything else, however, is believable. Leonard's motivation and desire to avenge his wife is understandable and doesn't require audience to take another leap of faith.
What about Harry Potter, The Hunger Games, etc? Those fall into the realm of fantasy and that genre is much more generous with disbelief.
So if you want to tell a believable ghost story, you already have one fantastical element - the ghost. Everything else needs to be realistic.
In my short horror story "Lady Winters' Mirror" in the Shadow People and Cursed Objects anthology, the mirror may or may not be haunted. That is the fantastical element in the story and I tried to make everything else as realistic as possible.