After shutting off all the breakers to the basement, I disconnected the wires and saw that a sharp edge of the metal wire mold covering had cut through the insulation and shorted it out. So decided to replace that section of wire mold with BX conduit (flexible armored pipe). I had some laying around, so was able to scab together a bypass for the shorted-out wires. The funny part was that after it was finished, it reminded me of the wiring hanging about in Dr Who's Tardis.
5 hours ago