I consider this project to be very safe, however, if you do somehow manage to injure yourself I am not responsible. Follow these instructions at your own risk.
Step 1: Get Materials
6' x 1" x 12" board (purchased this size at Home Depot) ~ $12
5'4" x 2" x 4" board (cut from 8" by Home Depot) ~ $6
Gorilla Wood Glue ~ $8
White paint and painting materials ~ $40 (used primer plus high gloss oil-based paint, high gloss is nice but oil-based paint is a pain and a bit expensive)
LED lights (http://www.amazon.com/gp/product/B0054U46Y2) ~$37
White Duct Tape ~ $4
2x 18" OOK Hangman metal wall brackets (mirror, picture and canvas hanger) ~ $30
Total: $137 (could be done for less)
Tools: clamps, levels, screw drivers, measuring tape
Step 2: Attach Boards
I used nails but they were too long and I had to remove them all. The glue is plenty strong enough to hold these boards together.
Step 3: Paint It!
I painted primer on the front and back. I only used the high gloss on the front and sides. If you do use oil-based paint make sure to get an oil-based primer.
Step 4: Attach LEDs
A quick word about LEDs--since they are highly efficient they don't get hot so there is pretty much no fire risk from the LEDs.
Step 5: Mount Light
These LEDs come with a remote which is powered using RF which means the RF sensor has to be exposed. I used white Duct Tape to attach the sensor so that it barely pokes out the backside of the front board. I also taped the small box used to power the RF sensor to the board.
I just let the power cord go down the wall but feel free to run it through the wall for a cleaner look.
A word about placement: if placed well the LEDs are not visible from any angle. For best results avoid walls with corners that bend away from the wall the light is on.
I designed this with horizontal hanging in mind but with slight alterations this could be hung vertically or diagonally.