Monday is Halloween, so this is a good time to dress up Google Earth in preparation. To do so download this KML file originally created by Frank back in 2006.
Here are also a number of spooky places to visit in Street View:
13th Gate Haunted House, Baton Rouge, Louisiana. See in Google Maps
Zombie Manor House, Manchester, UK. See in Google Maps
Diagon Alley from the Harry Potter movies. See in Google Maps
A pumpkin headed man on the streets of Paris. Be sure to explore, as he is not alone! See in Google Maps