Just don't put any HPS lights in that, have the whole box catch fire. That would be an interesting grow space though..
if you can be bothered getting 1-3 LED panels you could line the sides with them, heck, you could line 5 of the walls so the plant is surrounded by color (light). But you could try 1 LED panel, should go for about $30, of course aint the best but neither is a cardboard box.
I vegged in a cardboard box for awhile, just lined the inside of it with white poster board. Plenty of people grow in cardboard, it works fine with the right set up.
Im growing in a cardboard box. I'm using LED UFL light (90W) as its low-heat and high efficiency light output.. But CFL would work too i think.. http://forum.grasscity.com/indoor-marijuana-growing/1059325-stealth-cardboard-box-led-grow.html
I've got a grow going in a small cardboard box with CFL's. Got 2- 26w daylight bulbs in it right now but have 2-65w soft white bulbs I'm going to be using for flower, I have a small computer fan blowing in to help with heat issue and even with the two big bulbs heat doesn't go above 85.