Decontructing a 'haunted' room
Suppose, for instance, that someone sees a shadow cast on a wall in low light and interprets it as a figure and hence a ghost. Once this becomes well-known, anyone else visiting the room who knows about the report is likely to be in a heightened state of awareness, either eagerly anticipating or anxiously dreading some ghostly encounter. So when they see a door open by itself, it will often be interpreted as ghostly rather than a draught. And if someone else hears the noise of a creaking floorboard, that too gets added to the list of ‘phenomena’. All these things, including the original shadow, may have a natural explanation but once the room has developed a reputation for being haunted they are seen in a different light. People may start going on vigils there, no doubt adding further ‘phenomena’ to the list. And yet, this room is not haunted at all, despite its reputation!
Of course, scientific investigative methods will track down natural causes of apparently paranormal phenomena. The problem is that, once additional ‘phenomenon’ have become attached to the original one they form a sort of synergy where the haunting reputation becomes bigger than the sum of its parts. Even if all the separate constituents of the ‘haunting’ are explained, some people will continue to believe the room is haunted.