I have an AA in electronics and have done years of technician level troubleshooting of complex electrical circuits. At 5v or 12V, not 120v, 240V, etc… but the experience is there. A house is relatively easy to troubleshoot compared to an amplifier or power supply or CNC machine.
I understand Ohm's Law, multi phase circuits, power calculations, electrical interference, the practical effects of inductors and capacitors in circuits, etc etc etc.
I have taken 300 level math classes. I'm good with math.
I'm quite comfortable with multimeter (and oscilloscope, etc) usage.
I'm comfortable with reading schematics.