Designed this to go inside the enclosure for my Printrbot Metal Plus. I didn't print with supports, but should have for the mounting tabs. I ended up mounting two of these inside the enclosure, one above and in front of printer and one above and on right side of printer. I'm powering them off of a 12V AC to DC adapter. Details for wiring are in photo.

Its designed to hold 4x superbright white 10mm LEDs - the one I used: http://www.ntepartsdirect.com/ENG/PRODUCT/NTE30071

The holes angle the LEDs for maximum coverage.

In case you want to tweak: https://tinkercad.com/things/7cvRAkOKefX