In "The Turn of the Screw" is the governess crazy?

Could the governess be hallucinating? Besides actual ghosts, this is the other popular theme to which many critics point. There is evidence in the novel that perhaps the governess is seeing things. First and foremost, there is the fact that nobody except for the governess has ever plainly stated that they have seen ghosts. The one time that the governess thinks she will be vindicated, when the ghost of Miss Jessel appears before her and Mrs. Grose, the governess realizes she has a "thrill of joy at having brought on a proof." However, the housekeeper does not see the ghost: "What a dreadful turn, to be sure, Miss! Where on earth do you see anything?"

The governess herself hints at the possibility of madness at other points in the narrative. When she is describing the state that she is in after the first ghost sightings, when she is watching in "stifled suspense" for more ghostly occurrences, she notes that if this state had "continued too long," it could "have turned to something like madness." The governess faces a much longer dry spell, in which she sees no ghosts, during several weeks at the end of the summer and early autumn. Although she does not describe herself in "stifled suspense," she does say that one would think that the lack of ghosts would "have done something toward soothing my nerves," but it does not. If one uses this and other examples of the governess's nervous condition, the ghosts can be explained as hallucinations.