Remix from DB9 MicroUSB by ztxdk 

Added a internal washer to spread the nut and bolt load on thin walls of lightboxes. Also added a negative part to add/deduct from the lightbox wall (or back) for the micro USB board housing to slot into and also leave room for the screw holes. 

The negative part should also be big enough to feed most LED strips through so you don't have to wire up the board in place.

I found it easier to drill 3mm screw holes after the model has been printed.

Parts list added.