With christian haunted houses, and Jesusween, maybe it's time for an Atheist Haunted House.
We could scare kids with all sorts of theist behavior -
Burnings at the stake
The Inquisition, with torture chambers
and a special section with Rick Perry and Michelle Bachmann.
This has ME scared. Whooooooooo!
I think the easiest route would be to just stand outside the exit of a christian hell house. "Hey kids! Wasn't that guy nailed to the two by fours at the end the scariest or what? Well lets discuss what this place illustrates about the terrifying realities of christianity..."
Carve a picture in a pumpkin, with the face of the virgin mary in it.
That way, after it starts to decay a little, and gets slightly distorted, you can take pictures of it and sell it on ebay!