For those considering adding lights to structures having interior detail, you might want to give this a try:
Try using small diameter brass wire to provide power. The positive and negative leads of your lamps can be attached as shown. Then run your brass wire down a wall or support through the base of the structure to beneath the benchwork. The leads can then be hooked up to a power source easily and out of sight. The wire can also be painted to represent electrical conduit. This works especially well for those foreground structures having removable roofs.
I love the cluttered look. I wish I could get my wife to appreciate it when my own workshop (the 1:1 scale one) looks like that.
Is that one of the miniatronic lamps? I bought 6 of them, and 5 have burned out with limited, lower-than-rated-voltage use. Have you had better luck, or is it a different bulb?
I like using 1.5 volt lamps for two reasons. First, they shine with less intensity than do 14-18 volt bulbs do. As a result, the look more realistic. Second, the lower voltage increases the life of the bulb much more.
White Leds are the real ticket. They can also be filed, turned, and otherwise modified and modeled into shapes and seem to last forever given proper voltage. Here’s an image of one Led in an O scale shack. 
I also have some LED starter kits on my site ; http://www.2guyzandsumtrains.com/2g/beaverhole/traintronics/
Great idea Bob. I had a hard time finding the wire in the photo.
Beautiful interior detailing, Bob. Wow!