We recently bought a 2 story red brick (w/ attic and basement) built in 1941. While investigating issues with added hum in my guitar amps we found that 90% of the outlets in the house show an open ground issue on the tester. The wiring is a mess, there are multiple fuse boxes and a mix of "knob and tube" and more modern wiring. We plan to have the hole house rewired eventually but need to have a new roof put on first, i cant deal with the noise issues with my guitar amps untill then though. I was thinking maybe i could just have new wire ran to my music room for now. Could running new wire to that room including a ground fix the problem? Would it be as simple as running conduit through my basement wall and up the outside of the house to the attic and then down into the 2nd floor music room outlets? Any idea what it would cost me to have someone do this?