Series 3 Two brake light switches?

I'm a new Land Rover owner with a 1980 Series III. Had some issues with the brake lights so a few searches on here and had a play around with the brake light switch and think I've sorted it.

However, I have 2 brake light switches (see picture), and have no idea why - can't see any information online as to why there might be two. Any suggestions from the knowledgable people here?

Where does the servo vacuum tube connect to?
Wondering if someone has fitted electric vacuum pump!
Other than that follow the wires or disconect one to see which is actual lights.
Has it had a high brake light fitted at some point?

Thanks @Blackburn . I'll check the vacuum tube tonight.

I've disconnected both switches, and one is for the brake lights, the other does nothing when I disconnect it. I did wonder if it was for the towing electrics, but no idea why someone would have put a separate switch in for that.

Will keep testing.

Could be many things,
Extra brake light though why I have no idea, though maybe electric trailer brakes
Low vac pressure switch/warning
Some sort of disabled control
Some sort of cruise control cut off
Some sort of pto cut off

Have you traced the wires? checked the wiring diagrams online

Some late Series 3 had a "pedal travel switch" fitted as well as a normal brake light switch.
The idea was to bring on the brake warning light if the pedal was pressed down too far - e.g. if there was a leak somewhere in the brake circuits.
Hopefully, most drivers would know that this was a problem, without needing a a warning light...
The switch wires should be black/white. If you still have the brake warning light in the central dashboard, try connecting the second switch wires together and see if the light comes on!