Yeah, I installed a 13 ft. length from Home Depot about 8 years ago in my Ft Knox 16-gun safe. (that I have since found will hold at least 20 guns with some creative arranging)
Used the pre-existing hole in the left rear that fed the Goldenrod powercord and ran the rope-light in their plastic channels that have the double-sided tape already installed to the inside front lip.
Just enough length (and all you'll need) to go around the left side, upper, and down the right side. You can't see the lights when the safe's open unless you stick your head inside and look out.
Was a little dubious about how long the tape would last, but it's still holding on tight.
Downside: two, 1-foot seperate lenghts burned out within 2-3 years but there was still enough light to find your way around without too much trouble.
I just replaced the whole length with the exact same item about 3 months ago for a grand total of about $13.95 and I'm back on the case.
The only really tough part was drilling and installing a "door-jamb-switch" so that the light came on when I opened the door.
Burnrd up a couple of carbide bits getting through the steel but it worked out okay.
All in all, it works for me and since the safe is in a closet, I couldn't see crap without the rope-light deal.
Besides, I got tired of trying to find a flashlight every time I wanted in.
Pretty easy fix and you'll amaze your friends!