There's more than one way to skin a cat. Today I was wandering around the fishing section of a sporting goods store and came across a tiny little light made for night fishing with a bobber. It's basically a small battery with a bulb on top mounted in a push/pull switch. You push the bulb down and it comes on. Pull it up and it goes off. The package says it's good for 21+ hours.
Well, I got to thinking about lighting up the front sight on my Great Plains flintlock so I could use the Lyman 57 peep at dawn and dusk. At $2.99, I just had to buy one. Here's what they look like out of the package with the light on.