I'm surprised that I've received no replies to my "68 Signal Lights Not Working" question, but now I have another one...
The other day, I decided to drive my 68 to work and it quit on me a block away from home. I figured it was just a cold carburetor thing, but as it turns out, ALL electrical went dead.
Following some preliminary investigation, I discovered the dome light is out, the switch does nothing, the lights won't come on, and not a single fuse in the box is hot. Sounds easy, but then I found that the horn works, the battery lights my tester at the battery and at the starter. I've performed no other tests yet. I guess I'll start by testing the battery, but after that, I'm not sure where to go next.