Spooky sloppy contractors

DIY fixes for "professional" microwave installation.

My over-the-range microwave stopped heating food all of a sudden. So I took it down to poke around and see if I can fix (or replace) it.

Behind the microwave, I discovered this:

Yep, just a hole in the wall, a metal vent directly to the outside, missing insulation, and a hidden junction box that is just laying loose inside the wall. No wonder the microwave looks a bit rusty on the inside of its frame.

Closed up the vent with a piece of foam insulation.

Trimmed all drywall edges to be more straight. Cut out a bit more around studs to attach the new piece of drywall.

Added more insulation, attached the junction box to the stud.

The junction box is a bit baffling. It only joins an older wire to a newer wire, which runs further down, presumably to the outlet for the range. So whoever did this knew that wires should be spliced only within boxes (National Electrical Code forbids to leave spliced wires in walls)AFAIK), but, for some reason, did not bother attaching the box, or making it accessible. (Although, "accessible" might be bending the rules a bit here, since it's technically not covered by drywall, and is "just behind furniture")

The most proper way would be to run the old wire up into a junction / outlet box in the upper cabinet, connect the new wire up there, and run it down to the range.

Patched the opening with imprecisely-cut piece of 5/8" drywall.

And some duct tape for good measure. Yeah, it's questionable, I could have used joint compound instead.

That's a little better.