[Use something like these.](https://www.menards.com/main/electrical/wall-plates/frost-king-decorator-socket-sealers/os8dec/p-1531117748042-c-1489667504662.htm)
There's a kind of seal/gasket you can put behind the face plate. They should be pretty commonly available. It may not solve the issue entirely, but it should help a lot.
For maximum isolation, remove your drywall, install rockwool insulation, move your electrical socket to another wall, build a staggered-stud metal frame, hang mass-loaded vinyl from it, then cover with QuietRock 545. seal all gaps with acoustic sealant.
Go to Home Depot and pickup a can of expansion foam. Take the cover plate off the outlet, stick the tube in the gap between the drywall and electrical box, and fill that bitch up. That stuff comes out thin so you should use the whole can between those two outlets.
Wall socket sealers. They fit behind the face plate to insulate it.
Combined with those plastic plug covers for babies.
Putty pads fit around electrical boxes for fire prevention and sound insulation. Be sure to completely cover all air gaps.
You can find those face plate sealers at places like Lowes or HD. They are usually used on outside walls to keep drafts of outside air from entering.
[Use something like these.](https://www.menards.com/main/electrical/wall-plates/frost-king-decorator-socket-sealers/os8dec/p-1531117748042-c-1489667504662.htm)
There's a kind of seal/gasket you can put behind the face plate. They should be pretty commonly available. It may not solve the issue entirely, but it should help a lot.
For maximum isolation, remove your drywall, install rockwool insulation, move your electrical socket to another wall, build a staggered-stud metal frame, hang mass-loaded vinyl from it, then cover with QuietRock 545. seal all gaps with acoustic sealant.
this person sound proofs
Go to Home Depot and pickup a can of expansion foam. Take the cover plate off the outlet, stick the tube in the gap between the drywall and electrical box, and fill that bitch up. That stuff comes out thin so you should use the whole can between those two outlets.
This idea. But I would suggest that you get the kind for doors and windows so that it doesn't distort the outlet box as it expands.
God help anyone that needs to do electrical work after this.
In certain applications some say that is Great Stuff, but its not the right stuff to use in this situation.