Hi Everyone,

I hope this background info helps, if not you can jump to my question is at the bottom. Thanks so much for your input!

My background:

I have a professional background in low voltage electronics, I am a certified cable installer and have a strong IT background. I know how to fish cables, use a multimeter, read schematics, how series and parallel circuits work and the importance of having a grounded circuit. I am confident i can do basic electrical work with a little guidance. I do not want to call an electrician each time I want to swap out a fixture or upgrade an outlet or switch.

House Background:

I recently purchased a home that was built around 1980, the owner has done many renovations and all electrical work himself. He did a great job and I’m very happy with my new home. During the home inspection though, they had to replace the breaker box / electrical panel because live wires were exposed, and they had to replace the kitchen outlets with GFCI outlets. Once I got the keys, I hired my own electrician to check for potential fire hazards and a few things I noticed, like confusing switch configurations (outdoor security lights on same switch as a closet light, many outlets unnecessarily connected to dimmer switches, 2 switch plates that are a little warm to the touch, rooms with recessed lighting on multiple switches, etc.). I realize that some configurations were customizations that probably worked for the previous owner, but others are clearly the result of shortcuts.

i have a plan with my electrician to fix everything I mentioned above (except the warm switch plates, which he said was a non issue).

Here is my dilemma:

I am in the process of adding an outlet directly above an existing outlet in the dining room / kitchen area (for a tv I mounted high up). There is a double switch near the existing outlet; one switch controls the the patio outlet and lights, the other is a dimmer switch that controls the recessed lighting in the dining room. There is also a ceiling fan in the dining room that might have been on a switch at one time, but is currently pull chain only.

Heres what I did:

I turned off the breaker for the outlet, verified both top and bottom outlet have no power (using a plugin radio). This breaker also turned off the GFCI outlets in the kitchen. Everything the switches above this outlet controls (patio and dining room recessed lights), and the pull chain ceiling fan in the dining room is still on.

I know how to add an outlet when there is 1 hot, 1 neutral and 1 ground, but this outlet has 2 hot wires (each connected to the brass screws), and 2 neutral wires (each connected to the silver screws), and 2 ground wires joined together with a pig tail connecting to the ground screw.

Here is my question:

I would like to know if I can pigtail all 3 hot wires together (2 existing plus my new one), all the neutral wires together, and the same for the ground wires, with a bigger box?

Why didn’t they didn’t just pigtail both sets and only connect one set of wires to the outlet?