If you look closer, you’ll probably find only the outer protective layers are cloth; I’ve seen that on a lot of older wiring, but the ones I have seen all had a thin inner layer of rubber right on the copper. Tarred cloth probably would work, as long as the voltages were low enough and there were multiple layers; paper might be even better though. (Most of the old wiring I have seen was a thin layer of rubber next to the copper, then paper wrapping protecting the rubber and separating the individual wires, and the whole bundle protected with fabric.)
If you look closer, you’ll probably find only the outer protective layers are cloth; I’ve seen that on a lot of older wiring, but the ones I have seen all had a thin inner layer of rubber right on the copper. Tarred cloth probably would work, as long as the voltages were low enough and there were multiple layers; paper might be even better though. (Most of the old wiring I have seen was a thin layer of rubber next to the copper, then paper wrapping protecting the rubber and separating the individual wires, and the whole bundle protected with fabric.)