I've seen many plans for 50 Ohm dummy loads in paint cans, such as the one here: https://www.nonstopsystems.com/radio/frank_radio_antenna_dummy.htm. I've already assembled a functional dummy load, but have avoided using it at full power because it's currently resistors attached to copper plates in open air.
I'd like to move the entire thing in to a paint can (as in the link), but have a concern. It appears to me that the can itself becomes connected to one side of the dummy load. Couldn't this allow high voltage (relative to the radio) to appear on the can itself? Is there some insulating factor I'm missing? Would another material (such as a plastic project box) be a better choice?