None of that should be affected when the switch is flipped, that's the bit I'm struggling with. Sure, connecting a wire somewhere could act as an antenna but attaching a switch to the unconnected end of the antenna can't do anything. It's very weird.
> The switch could be connecting ground trace to the casing
This seems most likely - that there's actually a conductive path on one side of the switch from the switch body to the metal frame it's bolted to, so flipping it does take the frame in and out of circuit (doing something like changing capacitance or introducing RF noise on the ground plane which something in the PDP is sensitive to.)
> The switch could be connecting ground trace to the casing
This seems most likely - that there's actually a conductive path on one side of the switch from the switch body to the metal frame it's bolted to, so flipping it does take the frame in and out of circuit (doing something like changing capacitance or introducing RF noise on the ground plane which something in the PDP is sensitive to.)