Many years ago I had two Linksys devices. A router and an access point. They were both that blue and gray chassis style. (Like the original WRT54G, except these both predated that model).

They had the same size barrel connector. I was fumbling around under my desk getting everything connected when I let the magic smoke out of one of them. Turns out I gave the 9V unit 18V from the other’s wall wart.

That may also have been the day I learned the phrase “magic smoke”

Never were much into electrical engineering, to my own chagrin.

I can one up you. Verilux sells a "happy light" SAD lamp thing, still sold at Costco, which uses a mini-USB plug, running on 19V 300mA or something.

Yeah. How the FUCK does the USB Forum not shut that down?