Lighted cigarette lighter?

[CG]

Originally Posted by GMCPaul

In image above on left side of cigarette lighter housing you'll notice a small rectangular box of metal, the bulb to illuminate is under that cover. When cigarette lighter element is removed from housing it triggers bulb to light so you can find opening in the dark to replace element.
Paul Jr @ GMCPauls

Thanks, exactly the explanation I needed. Now I get it.