[morzh]

In this one both lines go to the power switch, so swapped all you want - that won't help much.
Polarized plug.....not much safety in it.
Also mistakes in house wiring when Hot and Neut. are swapped are common.

Better yet (found this one doozie in my house), when some idiot wires the hot and neutral in the same line from different breakers. Guess what happens when you think you switched it off