I'm not an electrician but have done most of the renovations and maintainence for this house. The customer initially asked me to replace an "ugly" tracklight with a new fixture (light #1). I pulled the old fixture and tested the wires - this is when things became interesting. I asked if it had been working. The customer then told me the bulb "blew up and threw the breaker." The tracklight was mounted on the ceiling some distance from the (open) box, with two wires connecting it. I checked the tracklight, and it's OK. A bare wire ends at the box. So, that's a single cable (black, white, bare) to this box, and I'm sure it comes from a buried junction box somewhere.
Everything on this circuit works, but I'm hesitant to just put in a new fixture, because I can't make sense of the voltages listed above.
Much of the lighting in this house has the neutral switched.
