I have a Cooper combination device which is a single pole switch with a pilot light model 277V. One side of switch has 2 black screws the other side 1 brass 1 green and 1 silver. I have 3 wires that is my power source 1 white 1 black and 1 bare copper. I know that the black goes to brass white to silver and bare to green. Switch will not work. Confussed with 2 black screws. Dan

That switch requires a neutral. If you have only black, white and ground wires in the box, you have a switch loop and do not have a neutral.
You need a neutral for the pilot light to work.

There are lighted switches that do not require a neutral. Do you really need the pilot light?