I'm a tough guy, and I'm afraid of very few things, but I am afraid of a cat sleeping on my face at night and suffocating me. And ghosts. Ghosts are scary as hell. Well now I can get a cell phone strap ($17) that alerts me when it detects magnetic field alterations or body temperature fluctuations. Unfortunately it alerts you with different colored light patterns and ghost noises, which will make me shit my pants. If it does go off though at least it's attached to my... WHO YOU GONNA CALL? Ghostbusters! Or, some a-hole with a laser cleaning backpack. Whichever is cheaper.
Ghost detector cell phone strap [tokyomango]