The investigation of an haunting case reported in the late 1960s by a widowed woman living alone is briefly described. The author recounts the initial visit of the Cambridge University Society for Psychical Research (CUSPR) investigating team, and their differing experiences. That is, one investigator saw a ghost which coincided in appearance but not in actions to the description given by the experiencer, even though that investigator had not as yet heard the description. The other investigator, on the other hand, who did know how the ghost was supposed to look and behave, saw nothing. The author deals briefly with the question of what is perceived in such investigations, in particular, what to make of differing and similar perceptions, and how details of these support the hallucinatory or telepathic theories of haunting apparitions.