My daughter who is now a headteacher , once worked in an old school in Essex where ever so often a child who went to the toilet during a lesson (unaccompanied) would report that an older girl/lady in what sounded like Victorian dress would approach them. This had been apparently going on for years.
Members of the staff when alone often felt somebody else was there when they were in that part of the school. My daughter never risked being alone in that part of the school , as did other teachers. All educated people . -Steve