Currently I have two wires running through the conduit: one hot (coming from box), and one hot switched (on/off according to light switch). I would like to convert it to an outlet switch combo (one outlet with a switch). So, I need to run one more wire, the neutral, to power the outlet.
The existing wires are old so I've removed them.
What wires should I use? THHN? What number (gauges), I'd say 12 is the suggested for outlets? Solid or stranded?
I mistakenly bought a 12/3 romex cable, which is too thick to run through the conduit. My understanding is that I can't strip the yellow plastic sheath that covers the wires, and just use the black, red and white wires, correct? Because I believe they don't have enough protection against damage. Correct?
What would be the right wire for this job?
The old wire had some textile/cotton on the outside, and it seems this is no longer used. What was this cable for, and why it seems no longer used?
Any help is appreciated!