Plug for Garbage Disposal

[motogpfan82]

Hi all so I' am looking to add a socket for a new garbage disposal I purchased. It has a plug that can't be removed and unfortunately returning it to the store is not an option. My old garbage disposal that just died and is hardwired to the switch above the counter, see pics. I was hoping I could just disconnect the cord running from the garbage disposal to the switch and hook up a socket under my sink, but when I took the switch out I' am unsure how to do this? I think there are two cable in the box but can't really tell. I tried to undo the metal ring around the cables to see if I could pull from the bottom to separate the cables but neither would budge. I can see that at least part of the cable going down into the wall is armored with the metal around it but when it comes out the bottom in the cabinet is looks like a household cord. I also tried to see if I could remove the metal box from the wall to get a better idea of the connection but could found no screws or any mounting hardware in the box and it is solidly fixed to the wall somehow? Any help with trying to wire this plug up to the switch would be greatly appreciated, thanks for any help!