larryg's question has been answered: A-D trucks (1947-1955-st series): no fuses associated in/on the light switch.
This question then moved into Task Force trucks light switches, and if fuses were added to the lighting system.
bartamos has nicely outlined lighting-system circuit-breakers and fuses (or not) on Task Force trucks:
Task Force trucks
- 1955-2nd series: no fuse on the light switch
- 1956-1962: one fuse at/on the rear of the light switch
1956 Shop Manual:
"The 12-volt electrical system on 1956 trucks is basically the same as that used on 1955[i]-2nd series, Task Force, trucks.
The master light switch on the instrument panel has been improved through the addition of a fuse which protects the instrument panel light circuit."
Just in case anyone still wants to know.