Something that's haunted seems to have ghosts. Visiting a scary haunted house is a great, if terrifying, way to spend Halloween night.
Ghosts, or spooky apparitions, are what makes a place haunted. You might truly believe your grandparents' house is haunted, or it might just seem that way because of the scary creaks and groans in the night, the cobwebs in dark corners, and the dim lighting. You can also describe a person as haunted when she's obsessed with or tormented by something: "I was haunted by the memory of my cat killing that poor mouse."