Generalprints.com is sure to give you the heebie jeebies. I especially like that the black splotches on the red change colour to be red splotches on the white over the letters.
This "spooky" little card is available from tinyPrints. The play on the word Halloween is especially cute.
Giving a classy spin to the mayham that is Halloween, this invitation is also a tinyPrints creation.
Will you come to my (non-existant) Halloween party?