I'll probably beat this dead horse to pieces here, but anything by Midnight Syndicate is fantastic for soundscaping a party or haunt. You can 'mix' cricket, wind, forest, whatever sounds by simply having another CD looping on another machine.
OR, you could try your local Halloween stores and even walmart because they have soundscape CD's that have interesting sound effects. The one at Walmart is only $3, and some of the stuff is pretty cool. Some of it's hokey though so you'd probably need to burn a cd with what you want on it.
"In nightmares our screams are silent, yet all fallen angels hear us on their way down." --E. Riddle
"Autumn whispers to me. It always has." --E. Riddle
The Corridors: Where Halloween is Forever