Lifting ground on P12

It seems in many situations lifting the ground reducing the noise of an amplifier. I was wondering if, while using a P12, if I were to lift the ground at the wall outlet or lift the ground of the plug that goes into the P12 is better. Would this affect the P12 negatively? If I did this I would replace the breaker on the fuse panel with a GFCI breaker for safety purposes.

I suggest you are much better off tracking down and eliminating the ground loop causing the noise to begin with.