I have the same year and model rig. Here's what I think you are posting about
:
If you are asking about the switch that controls the main kitchen 12v overheads it is marked as "Ceiling Light" in the picture. The outside dimensions of the switch are 1 1/4" high by 5/8" wide.
Have you confirmed you need a new switch?
Referring to the link provided by DQDick look on page 232 of the catalog and I think you will find the switch there. I think either part number 212597 (12625) or 212633 (13405) might be it but I hope others can confirm.
Ozz, what do you think, please?