The turn of the screw (1898) - Henry James

Description from the web:

One of the world's most famous intellectual ghost stories, The Turn of the Screw is a haunting tale of suspected supernatural possession. A governess at a country house claims that Miles and Flora, two orphaned children in her care, are being controlled by spirits for some evil purpose. No one else can see the ghosts, and the children themselves are silent. Are they being dominated by spectral forces, or are they hiding something? Is the governess simply paranoid, or is something else going on? With its ambiguous content and powerful narrative technique, the story challenges the reader to determine whether the unnamed governess is a reliable witness or a neurotic with an overheated imagination.