Final answer:
Ghosts are found in various forms in literature, including as characters, plot elements, themes, and settings in different works.
Step-by-step explanation:
Ghosts can be found in multiple forms in literature. In A Christmas Carol, characters like Marley's ghost and the three spirits play a major role in transforming Scrooge. In The Turn of the Screw, ghosts are a plot element as they haunt the governess and the children. In Hamlet, the theme of ghosts is present through the appearance of Old Hamlet's ghost. Finally, in The Haunting of Hill House, the setting itself, the haunted Hill House, is filled with ghosts.