Can you say a few words about how you will make this connection to 120VAC Mains power safely? Where will you place the switch, will it be single pole or double pole? What fuse rating will you use and why? How will you handle the Line lead differently from the Neutral lead? Will your use of the AC Mains be singly-insulated or doubly-insulated? How does that affect whether you use a 2-prong or 3-prong power cord? How can the use of an AC Mains Isolation Transformer be useful in some test setups?I am going to supply 120 vac from an electrical outlet
If you don't know the answers to those questions by heart, you should not be tapping into the AC Mains directly as a power source.