Dome Light wiring
Figure A is with light, on off switch and door switches.
Figure B adds the wiring for the headlight switch when equipped.
Both allow the door switch activation to be turned off.
Parts required;
Dome light assembly;
Two door plunger switches
Center off slide switch; 
Slide switch in center position is off. Headlight switch still will work Dome light.
Slide switch in position #1 = light on.
Slide switch in position #2 = light on upon opening of door.
Courtesy of Automotive Component Engineering