Some ghost stories are true some are just made up. I have one I can tell you which is true. My friend lives where Big Arm Billy used to live. He died in the bath when he drowned and if you laugh at him he'll drown you in the bath! At night when my friend is sleeping she can hear footsteps around her house when her parents are sleeping. Freaky!
Scary, totally random moments, and the big build up to whatever the main part of the story is.
Your fears.
Scary Stories to Tell in the Dark has funny and scary parts in it.
The tempo and the chords.
It has some scary parts, but mainly, it is a very fun and exciting story.
Here are some scary things:familiar things that suddenly turn dangerous or aliensomething totally unexpected and dangerousknowing something is "out there" but not knowing what it ispeople getting killed and/or eaten
Scary story
Alcatraz
scary parts
Jason is scary because he makes a scary sound when he's getting closer to the person who is about to get kill by Jason
Whatever you want it to be about! You're the writer -- you need to write about what you think is scary.
If you tell a scary story in a pink house, it is not scary. Tell a ghost story in the dark, in an environment that puts people in an insecure state, for best effect.