I recently found this handy little light while at my local improvement store. It runs on three AAA batteries and by adding a couple of hook and loop tabs the the back, it attaches perfectly to the inside of my Lightware  camera case. So you are working in a dark set this can be a saver. I found this beauty at Home Depot. It was in the fluorescent bulb isle.

Utility light from home depot that works great inside the lid of your camera caseUtility light attached to the lid of a Lightware MF1217 case