78 C10 - what's the bulb under the dash called?

[jb3t]

Sorry for this seemingly simple question. What is the bulb under the dash by the ashtray called? Is it the courtesy light?

I am trying to look for a replacement bulb for this and unfortunately the one that was in there is completely destroyed. So, I am having a hard time finding a replacement bulb.

Troubling the matter is the search button is not available for me to do research here.