We all know those visiting demons are cute and all for Halloween, but what do you do when they outstay their welcome?  Furniture flying around the room, loved ones floating from their bed and uttering strange languages, it can all be such a hassle.  That’s where your friendly neighborhood exorcist comes in.  The practice of exorcism dates back to at least the 7th century B.C., but has seen a pronounced resurgence in recent years.   Joseph P. Laycock is an assistant professor of religious studies at Texas State University and a coeditor of the journal Nova Religio.  His latest book, The Penguin Book of Exorcisms, is out now from Penguin Classics.