Domelights in the sides of the pillars were standard.
The light package was a trunk light, a glovebox light, ashtray light, ignition switch light with time delay relay, and in 1970 up headlamp timer delay.
Not sure if the light package was available on the barracuda. I added it to mine. Theres a tab on the trunk driprail for a pin switch for a trunk light. Theres a hole in the dash frame for the pin switch for the glovebox door to contact against for the glovebox light. These may have been seperate items as dealer installed options, since plymouth was billed as a price leader, and this was to keep costs down.
The ignition switch lamp is activated when you open the car door. This illuminates the lamp over the ignition switch. The time delay relay keeps the lamp lit for several minutes, then the contacts open and the light over the ignition switch goes out. This is convienent at night to find the keyhole
The illuminated ignition setup requires a different door pin switch with 2 spade type prongs and 2 wires to activate. Standard wiring for the domelight without illuminated entry used 1 wire in a barrel type bayonet connector, and a body ground.
My 67 was not wired for illuminated ignition, because the schematics show it not have been available in 67 on A bodies. I added it in using various schematics from 68 and 69 darts.