>>11608531PLEASE PAY ATTENTION TO THIS POST.
That microwave you are about to tear open can possibly have high voltage, charged capacitors in it. If you short it with your finger, you're fucking dead m8.
You said it's an old microwave, so it's probably fine, but just so you don't join the darwin awards, make sure you discharge the capacitors. Look up a video on how to do it.
Also, the transformers in those things can produce absurdly high voltages for killing yourself, so I recommend that.