Can't run A/C at home: solved -- see 8/21/16 update

2oldman, my question is more basic than you think it is. I understand the need to compare the voltages under load and not. My question is this -- physically, how does one use a multimeter to test this? Where do you stick the two leads without getting electrocuted?

Sounds like a silly question, but I would bet there are a lot of non-experts like myself who do not know the answer.