old extension cord to a super extension cord
better, safer, never throw one away
video on youtube by stud pack
12 gauge wire extension cord or one that you would throw away
double gang box - drawn box (pressed, slides easier, smooth) not a welded box (square sharp corners, you can see welds)
ground fault
duplex receptacle
mud ring cover plate
strain relief from mcmastercarr
use a drill index to figure out the hole the wire fits in
junction box