Henry James 
The Turn of the Screw 

In Turn of the Screw a friend reads his recently finished manuscript to the unnamed narrator. The story tells of a governess being hired, she quickly becomes fond of the children in her charge. While spending time on the grounds of the estate, she begins to see the spectral figures of a man and a woman. After speaking to the family housekeeper, she learns that the old governess and her lover, who are dead, adored the children, and spent most of their time with them. She becomes convinced that the children are secretly aware of the presence of the ghosts. A spine tingle study into the nature of evil and sanity.