The window switch panels have a tab at the top that often is broken, making it loose. That might cause the squeak. Once you get the car, GENTLY pry it off starting at the top, wiggle it out, then look for missing tabs, loose plugs, etc. Drive it without the panel and see if it makes the same noise... could be something else in the door.
I just pushed on the one in my wife's car. I know it doesn't squeak when we drive it over the weekend, but when I push on it there is a little squeaking/snapping, kind of like a leather coat makes. I can't see how WD-40 on the points where it touches the door panel would hurt...
My wife painted the switch panels on the doors, radio/HVAC bezel, shifter bezel, instrument bezel, dash vents, defrost vent, passenger air bag, etc. body color on her car and I bought one that was already done that way. We like it. Let me know if you would like pics.