Hi! I'm putting in a GFCI receptacle in an old house. The wiring is 10ga and I'm having a really hard time working with it -- it doesn't fit well under the screws of the receptacle (Pass & Seymour Trademaster) and it doesn't fit well into the box, even though I calculated the box capacity and it should be okay.

What I want to know is: can I pigtail the wires so that the wires I'm attaching to the receptacle are 14ga, not 10ga? It's a 15a receptacle.

Thanks very much for any help you can give.

Yes you can pigtail down to #14, but, is this aluminum #10wire you have or copper? If aluminum #10 and #14 copper the splicing connector must be rated for splicing Al and Cu together. If both wires are copper, just need to be sure to use a large enough splicing cap to handle both CU wires.