Replacing ceiling fixture with track lighting

[tatiang]

My house was built in 1911. I removed the hanging fixture from the hallway ceiling to discover two black wires coming out of the ceiling. The ends were twisted around the two black wires from the ceiling fixture and then rubber insulation (?) and electrical tape were used to cover the twisted wires. I would like to add a track lighting system that uses a floating connector to connect to a junction box. It comes with instructions to connect it to the black, white, and green wires.

Can I do this without a junction box? Which wires do I connect together? If I use wire nuts, how do I determine the size that I need? What do I do with the green wire connection if I only have two source wires from the ceiling?

[John Nelson]

You must install an electrical box if there is not one there and one does not come with the fixture. Spend $15 on a voltage "tick" tester to find out which black wire is the hot and which black wire is the neutral. Make sure your fixture does not contain a warning that it requires 90-degree wiring. If it does, get a different fixture without this requirement (or post back for possible mitigations). Electrical tape no longer makes a sufficient connection. Use wire nuts. Yellow ones will probably be right. If you have no grounding wire from the ceiling, you'll leave the green wire unconnected and your fixture won't be grounded. It's not great, but it's the best you can do with what you have. Some day you should plan to rewire the house.

[tatiang]

Thanks for your suggestion! I bought a non-contact wire tester, but it shows both wires as live... is that possible? Can I just connect the white wire from the track light electrical box to one wire and the black wire from the track light box to the other wire? Is there any risk of fire if I pick the wrong wires?

If the track lights are NOT grounded and they hang as pendants, is there any danger if people touch them?

[John Nelson]

No, it should not be possible that both were live. Perhaps you didn't separate the wires far enough and the tester was reading one wire when you held it up to the other. Try getting the wires farther apart before you test them.

Connecting the fixture backwards (reverse polarity) is not a serious hazard, but it increases the risk of shock when changing bulbs. It does not increase the fire risk.

Ungrounded fixtures are more dangerous than grounded fixtures, but it's usually not serious with ceiling lighting, because people normally don't touch them. Are your fixtures such that they will come into human contact frequently?

[tatiang]

When we realized we had old "knob & tube" wiring without a ceiling box, we decided to go ahead and hire an electrician. We want to make sure it's up to code and safe!

[John Nelson]

Start saving money for a rewire. Unfortunately that will cost many thousands of dollars. You're not going to want to leave that K&T there forever. It will eventually interfere with your ability to insulate, to insure, to upgrade, and to sell this house.