I have a normal wall switch that controls half of a duplex outlet in my living room. The workbox contains three sets of NM wires: (A),(B),(C). Wire (A) has red/black/white/ground and wires (B) and (C) have only black/white/ground. The red(A) wire is attached to the top of the switch. All black wires go to a wire nut which has a tail to the bottom of the switch. All the white wires go to a wirenut.

I purchased an XPT transmitter base and am planning to change the single gang box to a dual gang box. I want to leave the original switch doing its original function, but want to take the incoming wires and use them to connect the new XPT transmitter. I presume I will just need to connect the black wirenut to the HOT on the new XPT and the white wirenut to the NEUTRAL and I'll be set. Right?

Thanks for any advice. My order will arrive on Thursday and I would like to be able to install it then.

-Mark