I’m aware of experiments where small groups of people were taken to old homes under various pretexts.... If the group were told by the “guide” that the place had a reputation for being haunted, at least some of the participants would report some sort of “incident”.....Noises, footsteps, whatever.
If a similar group was not so informed.... No incidents.
We have a building on campus, the old Chancellor’s residence, that’s been reputedly haunted for many years. Now and again, the burglar alarm would go off for no apparent reason (hardly unusual). So we’re checking the place one night and the reason for the alarms becomes apparent.... A bat has taken up residence in the place.
We had officers who refused to go into the place.