This is a 1985 home wired with typical NM-B wire and plastic wall boxes.
I have a few light switches around the house that have no ground connection. There are ground wires in the box, but the switches themselves don't have a ground screw. I guess this was a valid thing to do at the time, but these switches need updating.
To ground the new switches, often times I need to run a ground pigtail from an existing wire nut to the replacement switch. And I'm running out of 14-gauge copper wire scraps to do that with. I've searched all the local big-box stores looking for 14 (or even 12!) gauge bare copper rolls, and I can't find any. I can get insulated THHN or NM-B with no problem, but stripping eight inches of insulation off of that seems like a real chore unless I'm missing a trick.
One thing I did see — they sell rolls of green-insulated THHN in appropriate gauges and lengths. Since green universally means ground, can I use that for my application?
Separately from the question of whether it's code-compliant to do, if a seasoned pro came by later and saw something like that in the box, would they think the previous work was done by a knucklehead? I ask because I've never seen green wire used in residential wiring, either in this house or anywhere else I've ever lived.
Best Answer
Green wire is perfectly legit. If you are really lazy or in a hurry you can even get pre-cut pre-stripped green grounding pigtails ready to go.
Ground is the only thing it can be used for, but "green or bare" is fine for ground nearly everywhere (I think there are some hot tub/pool specific cases where green is required and bare is not OK, but I don't have any detailed familiarity with those installations as I don't have one.)
Incidentally, it's trivial to strip long lengths of wire with a utility knife if you clamp the end of the wire and pull as you cut. I opted to go full conduit and have been using the NM that was partially installed as grounds (where needed - most of the grounds are the EMT conduit itself), and can strip a 12 foot chunk in less than a minute. I detest the scam where the THHN inside NM cable is not labeled as THHN so it cannot be used any other way...