A device only draws as much amperage as it needs — plugging a device with a 120V/15A plug into a 120V/20A outlet won’t hurt anything. It just means that you can ALSO use a device that draws up to 20A. I’d be scared if I saw normal-sized outlets where one prong is horizontal, the other vertical. That means 240 voltZZZZ.

On the other hand … my dad’s first apartment in NYC had some outlets that were still on the city’s direct-current grid, and looked exactly like normal outlets. Plugging in a lamp was fine. Plugging a TV set into one of them caused the TV’s transformer to melt down.