Dumb questions:

Model: GCX1226-120
22 mm metal, illuminated, red, 120 Volt AC/DC, 40mm mushroom operator, latch with twist-to-release, 1 N.C. contact block

Questions:
1. Does this mean I don't need a latching relay? Or, do you always need a latching relay?
2. If you have only one N.C. contact block, do you just run your hot side of the AC through it? Hit the switch and the power goes off? No other circuits needed?
3. My Power supply takes 220V (which is really two 110V AC and a ground). Some of the Buttons at automationdirect have stackable contact blocks. I assume that means I could run the 220V through it by having each 110V side go through a single contack block. Is that correct?


Thanks for any help...........Sam