Why is Horn switch 12v- on 10mtr

[my10meter]

So in my dash rewire I get to the horn. The horn pushbutton has 12v negative to it....Any input as to why? I am going to wire it this way but just curious as to why

[prowlersfish]

Sounds strange , do you have the wiring diagram ? If it has a relay using a ground is common in the automotive field . 2 wire switch ?

[my10meter]

It is wired into a relay type setup for the high water alarm. Trojan schematic even show it as 12v neg

[WayWeGo]

Not having the schematics, I am guessing the high water alarm activates by completing a circuit to 12V ground. If that is the case, the horn switch would also be wired that way.