Chuck, I have used the Walthers HO Cornerstone lights available in almost any hobby shop, and they work just fine. They come 3 in a pack, and have the little S shaped mounting bracket. You can repaint these if desired as they come in a dark green color. They are 12V, but I run them on 6V, and they are plently bright, without being over powering. Even though these are HO items, they are perfect in O scale for over doorways, dock doors, or even building signs.