Looking at that plug and how chunky the holes are for ac power, when access is limited and you can’t see, shoving a usb c plug into the ac hole is going to happen often.
You'd have to shove awfully hard -- hard enough to crumple the metal shell of the USB connector, since it's wider than the opening in 120VAC socket. (I just tried it with a spare electrical outlet, and even with a fairly hard push and wiggling it around, I couldn't make it fit)
Yikes and thanks - I’m in New Zealand and our plugs are way smaller so you couldn’t make that mistake here, but it’s good to know the terminals are far enough in that it’s safe.
I’ve seen some surprising things people have forced into the wrong port. USB into Ethernet etc.
The long vertical slot you could come in contact with is neutral. The bottom peg is ground. The top right vertical strip is hot but it also has recessed connectors and is smaller than the usb c connector.
I'd be impressed if you could cause a short on purpose with significant force let alone fumbling in the dark.