You state with every combo of amp and git ... but have you tried a different instrument cables also ?
Also another couple more diagnostic steps to try is to try turning on the amps with no cables at all attached and then with no guitars but different cables attached
While anything is possible It would seem highly unlikely that both amps would develop an internal grounding issue unless you drug them behind the car during the move
And the hum stopping when you touch the strings or jack (with all combinations ? ) If yes, then it would seem almost certainly a grounding issue related to something in the house circuitry . Although I suppose it could still be some kind of hum from power lines or other RF issue.... So taking them somewhere else is an excellent diagnostic suggestion as well as are Gmountains suggestions