Clarification/Follow-up by ETWolverine on 04/18/06 7:56 am:
According to the story "The Dybbuk", the evil spirit exited the body of the victim through her fingernail, and smashed through the closed window, causing all sorts of damage (not the least of which was the broken window itself). The lesson to take away from that is to leave the window open so that the dybbuk can escape more easily upon being exorcized.

Elliot