I took the driver's door panel off to change the front mid-bass drivers. There's an orange plug-in bulb, (connected to a pair of wires) that wasn't inserted anywhere. It lights up when the headlights are on. Where does that go?

I should mention that it looks like the window/mirror control panel was swapped at some point as it's got a mirror fold button, (an option I don't have one the car). The control panel is already illuminated. Was the orange bulb used with an older panel and no longer needed, or does it go elsewhere?

__________________
2014 BMW 328i Xdrive
2011 BMW 335i M-Sport
2008 BMW X5 4.8i Sport
2000 BMW 528i 5sp