Turn signals fixed! another something curious found

[Rose Mary]

Group
my daughter and I took the top front panel down above the windshield.
They were mucking around in there Friday at the shop.
Anyway found the flasher and a wire was loose....how many hours labor
should I charge them for running down the problem they left!!???

While we were looking around up there, (still hoping to get the
musical horns back...) found a toggle switch, just laying up there.
When you toggle the switch it turns a bright yellow light on above the
pyrometer...???? any ideas what this is for?

thanks all
Rose Mary
82 FC 35
JP's White Bird
Oregon