Metal Junction Boxes and 2-Wire Romex
I have quite a few metal junction boxes in the unfinished basement of my 1940's house. Some have new NM-B running into them, some have the original 2-Wire Romex (with braided cloth insulation), and some have both.
When did the NEC require that metal junction boxes be grounded? Some of the metal junction boxes I have are really quite old with (what looks like) soldered and taped splices, and I'd imagine they were done to code. Am I required to bring these junctions up to the current code by putting them in PVC boxes?
I have one set of exposed splices in my basement, with 3 #14 non-grounded Romex wires splicing together with wire nuts. Because I have no ground path back to the fuse panel, I cannot instal in a metal junction box. Therefore, I have to use a PVC box.
Can I use a plastic switch box, or a round ceiling box, or does it not matter, as long as I have the correct capacity for the wires and connectors?