Where is the switch (in cabinet, countertop,..?) where is the outlet(s), how large are the box(es)? Red and black are both hot, white is return (nuetral) bare is ground. Run black to switch and continue to outlet copper color screw, red wire goes on other copper color screw, BREAK out tab you will find between the two screws, white wire to light colored screw, DO NOT break out tab, bare wire to ground screws on switch and outlet and box if metal.

pretty much but be sure you have the correct voltage. Solenoids come in all flavors. If you connect a 12 volt solenoid to 120 volts, you will smoke it.

Is there anyone on this thread still? Here is my issue. Bought an older 2 person tub. It has a 4 wire seemingly 220 wire coming from tub--goes in to a timer box where the terminals are dbl and tripled up going through those circuits--then the plug for that box coming out of it is a 110 plug and that is the only plug giving power to the tub through the timer box. Has this tub effectively been already wired for a 125 /110outlet and I can just plug and play? Am I safe considering the 125 plug does have a built in ground through it?

Yep. But there are some tricks to minimizing the damage. Understanding what the structure looks like behind the drywall can help to find the optimal route and determining if there will be any obstructions in the way will also help (eg. HVAC ducts, plumbing, etc). Sometimes the shortest wire route may not be the one that minimizes the damage. Wire is cheap so taking a longer route may be advantageous. If you have big baseboards or crown moulding, then pulling that off and boring the holes through the studs to move the wire horizontally on the wall, then re-attaching the moulding can help minimize the plaster/drywall repair. But ultimately, drywall repair is pretty easy unless you have a texture. So just punching holes and fixing them isn't that big a deal.