I've got two fancy old strings that use bulbs with threads that look like standard flashlight bulbs. I still have a few replacement bulbs but if they ever blow... I doubt I'll get those fancy yellow, purple, green and blue bulbs any more. The sockets are a bit loose, so i have to retighten all bulbs each time I use the strings (pretty rare). IIRC 16 bulbs in series, no bypasses. Round ungrounded plugs. I'd never put them onto a christmas tree (most people here don't really consider colored lights on a christmas tree really high culture, still lots of real candles here) but they make real great party lights, I think the last time I used them was a birthday party. They always somewhat remind me of "Eyes Wide Shut".
