This battery case wrapped in an LED light strip is really bright, with 75 LEDs. It is powered by a 9v and two AAA batteries.
Just add a rocker switch, an LED light strip with adhesive backing, and 10 inches of 18 gauge wire.
Instructions at http://youtu.be/R63sVpQD2s8
Print the parts using 2mm layers.
You'll also need two 3in. (8cm) pieces of bell wire that is two pairs of wires); two 2in. (5.3cm) strands of 18 gauge bare copper wire; a single pole switch; a strand of 75 LEDs with self adhesive backing; two m3 X 10mm cap screws; some solder; some electrical tape.
Check out the youtube video "Ikea ROTERA LED light package" for detailed instructions. http://youtu.be/R63sVpQD2s8