If you truly ain't afraid of no ghosts, you'll want to download the free sound samples from the Ghostbusters video game that Microsoft is offering on its official site.
As a nice little Friday gift, Xbox Live's Major Nelson is providing four audio clips from the game, in both WAV and MP3 formats. You'll enjoy the sounds of The PKE Meter, Capturing Sequence and two clips of an angry Stay Puft Marshmallow man yelling out his barbaric fury.
Go ahead and use them however you want: Set them as your ringtone, or your error sound, or just blast them from your car windows at top volume as you drive around town. It will impress girls. Trust me; it'll work.