I saw an idea for something like this in BHG's Halloween issue and tweaked it a little. All you need is a piece of cardboard cut into the shape of a mouse with a hole for the eye and a battery operated tea light candle with the flame removed (use needle nose pliers).
I just hot glued the tealight onto the back with the bulb poking through the eye hole. Then I hot glued an extra piece of cardboard on so that my mouse can stand up.
Turn the tealight on and you have a creepy mouse with a glowing eye.