Paul,
That's a really good point!.
I use neoprene covers over the EHT part of the microwave, when I'm working on them.
I remember making a Jacobs Ladder out of a microwave oven supply and a few other bits,
and it worked well, until the ladder wires shorted together. [Linked Image]
Won't be building one of them again, for a while, anyway!. [Linked Image]