Originally Posted by Ash
Cant you just install sockets with 2 holes if you dont have ground ?
I don't think you'll find any outlets without ground any longer. Why don't you ohm out the ground in the existing boxes?
Check the resistance (with the circuit dead) between the box and a known good ground, such as a newer outlet's ground.
I have tried using the thin "tracer" wire in old BX cable, and I could not attach it to the green ground screw in the box without having it break. I ended up doing what the previous electrician did- just wrapped it around the outside of the BX, then attached the clamp.
I checked the grounds, and they are good.
For all new work, I always use NMB cable.