Years ago I installed some undercabinet lights that were like a track, and you could plug bulbs anywhere along the track. I suppose the only limit was the transformer. At the time it was the only light system I could find with 1/2" knockouts for connectors. I keep thinking it was called T12, but that's a fluorescent bulb, and these were halogen two-pin.
Any help would be appreciated, I've been searching for about an hour with no luck.