I was hoping to have this ready yesterday but I was ill and ended up cowering on the sofa for the entire evening. So I'm sorry that it's a little bit late but here's my Halloween offering for 2013: Nan Tuck's Ghost. It's a short adventure that should only take one evening to complete and is almost system neutral; there's one bit that mentions mechanics used in Call of Cthulhu, D&D, and Savage Worlds, but that's more an attempt to be helpful than anything.
Let me know how you get on with the adventure. I suspect it will be quite deadly; when I played it there was only one surviving player-character and that's because they weren't present for the grisly finale. Have fun!