[fozzi97]

That’s your handbrake, are you sure it’s blue, it should show up as red on the dash if it’s on. What’s your make and model

I think he's referring to the small switch on the right, not the parking brake.

 

[fozzi97]

I assuming you've bought the car used? It looks like an aftermarket switch that the previous owner has had fitted to activate something on the car. It could be anything, for example roof lights if it was used in the highway maintenance industry. Definitely isn't a genuine switch that the car came with. Only way to find out is to chase the wiring behind it.