To ground or not to ground.

I have a small project consisting of RFID reader, some Reed switches, LEDs, a maglock, etc. It penentrates an outside wall to an exterior panel. It has a few power supplies - the negatives are tied. The PSUs all use two-wire AC.

Shall I tie that to earth ground? Ie: the green and yellow or bare copper wire?

Are all the PSU's double insulated? And of reputable manufacture? If so there's no requirement for
earthing, but you always have that option, and if the panel is metallic I'd suggest earthing it.

Agree with MarkT.

An additional concern is static discharge damage to the electronics if you do not ground the panel.

My panel is plastic. I think I'll keep it as is - not earthed.

Well, there is circuit common, and there is an earth connection. Any metal that can be touched or even a spark reach, should be connected to circuit common (colloquially called "ground"), but doesn't need to be earthed.

Yeah, the whole shebang shares a common ground.