Getting that noise from the guitar where when you touch the strings it stops, but also discovered that it only does it when the guitarist is holding the guitar in the playing position, i.e. the pickup is facing out away from the guitarist. Noticed that when we turn the guitar around so that the back is facing out, the noise stops. We're in a residential finished basement. I turned off what I thought would be all the possible sources of the interference but can't seem to figure out what's causing this. I ruled out any of the audio equipment because I plugged directly into the mixer and listened in the headphones. Any ideas or suggestions to find the source of the interference that causes the power hum?