I have an old house with unswitched knob-and-tube running to a ceiling fixture. Previous owners ran surface conduit to a wall switch and to a second light fixture over the sink; none of this was grounded, needless to say. I recently had to replace part of the ceiling, so I took the opportunity to remove the surface conduit:
- I Installed metal boxes with extensions for the original fixture and the one over the sink (I used expandable joist hangers to mount them)
- Ran shielded metal cable above the ceiling to connect the fixtures, and down the wall to a newly-mounted metal switch box
- Carefully routed the knob-and-tube wires through separate holes in the top of the box, secured them, flagged the neutral with white tape, then wired them to the fixtures and switch with wire nuts. (They originally just poked right through the ceiling and a surface plate)
I thought to route a three-wire lead up to the switch from the floor, but I still would have been left with a live knob-and-tube circuit in the ceiling. There are other fixtures upstream of the kitchen lights, so I couldn't just kill the whole circuit or easily terminate it upstream.
I'm pretty sure this is not to code, but it was the least disruptive method I could come up with. The wires are typically brittle, but they are essentially in the same position they have always been and connected the same way.
Here are my questions:
- is this considered an extension of the circuit? I did not add fixtures or outlets. I only replaced wiring that was itself installed after the knob-and-tube.
- What should I do with the ground wire? As it is, the wire sheaths, switch, and all three boxes are bonded together with the ground wires but don't connect to anything. Should I leave them unconnected, or otherwise signal that they aren't actually grounded? (This would be obvious in the main fixture box but not in the other fixture box or wall box.)
Thanks in advance.