If I want to install an LED rocker switch in the cab, what's the best way to do it. I don't have a designated blank to pop out and install one.

Drill and/or a small saw.

I completely goofed that question.
In my head I was thinking about the wiring, not the location. Might help if I actually mentioned that in my question I suppose....
I'll try again.
What's the best way to run the wiring into the cab so I can mount it below the air vent, by the driver's side door? I have a dimmer switch for the dash lights adjacent to this spot so there's room to install, just not a designated tab to pop out.

A 12v circuit is about the simplest thing you will ever wire. You need appropriate sized wire, various connectors, fuse protection, switch, and the light.

Watch a few youtube videos and go to work.

Running wires to engine compartment depends on style and year of truck. Usually you can find where wire harness goes through and push along side it. My 2016 silverado is double panel so I pushed through rubber housing around steering column and it seals itself pretty much. If using round switch use drill. If square/rectangle a dremel tool works well.

There may be a rubber grommet in the floor board. Poke a hole in that. Run wire down channel beside the door. Pop the trim off there may be other wiring in there too. Just follow it. Not hard at all.

Go through the fire wall. Insulate the wire very good. A short in a 12 volt wire will melt it down

Ahhh YouTube. Shoulda started there.
Thanks.

Some trucks have unused wires that are taped up in the engine bay and under the dash. You maybe lucky.

I would consider mounting the switch in the bed, where you will most likely be when you want bed lights. You could have two switches controlling them, but that’s a little more complex circuit. Led bed lights are unlikely to draw a lot of current, so I would just drop a fused hot wire off of your battery (this is also make them able to cut on regardless of ignition switch position) to the bed, switch the hot lead, and get your ground.

I was gonna have my son throw some lights in my truck bed but, I'm actually gonna order the AA battery one from this place I think. It's a light AND it's waterproof. If not, I'll tie into blinker wiring like they do.
access lights
^presslink^

This is what I did when running coax to my 2m HAM rig

Should have a couple of places on the firewall where the wiring harness(es) are ran through. They are protected by rubber grommets. You can run the wire through the grommets with harness wiring and to your mounting location.

Thanks for your suggestions.
Not sure why, but electricity and wiring have always been a source of confusion for me. Ever since I melted a pair of pliers and got knocked clean off a ladder I've been somewhat shy of all of it.

LOL, I got hit playing with a dryer messing with old wiring once. poopy hurt!

I actually ordered those AA battery lights

Let us know how you like them. I looked at them couple years ago and couldnt decide on which one to get. I wanted the battery ones though.

Roger

Run wires under kick panels to behind seat. Bore through bottom. Run wire through small diameter air line to bed. Use silicone to adhere wire under bed rail