Electrical - convert plug in to hard wire

Mic I'd think so

Assuming a whole lot, frinstance one phase, 115 v ac, etc etc

Yes, an voltohmmeter is a handy possession. You should get continuity from ground lead to appliance frame, hot (usu) to center of bulb sock, and (usu) neut to sock screw

Now be sure to switch from ohms to volts ac

Goin' the other way, hot is (usu) 115 v to either of the other two

Now be sure to switch off power

From a good, solid ground somewhere you should get 0v to the ground lead, then (usu) a few mv to a few v on neut

Best of luck

Yes fellas, my sons assure me I'm chancing a lawsuit