With Tuesday's post on the release of Dr. Sleep, I thought this article by Dr. Michael R. Collings on the key elements that make a great ghost story would be of interest.
Dr. Collings is an extremely well respected member of the horror community as a writer of fiction, poetry, and nonfiction about horror. He is currently the Senior Publications Editor at JournalStone.
Point being, he knows what he is talking about.
Collings writes regularly about how to write horror here.