I'd go get a prefabbed cabinet from home depot. the back should be a pretty thin material and easy to cut for ducting. Take the doors off and put up a nice big piece of white poly in their place. then put the zipper up and maybe caulk the seams inside and you'll definitely be light safe. the cabinet should be white so no need to put up poly or mylar. I'm not that great with tools either and I built my cabinet in about 3 hours :stoned: