What does one do for the MC brake pressure emergency light switch?

there is a third port on the botton that you could use with a pressure switch, or use a mechanical switch on the rod that actuates the brakes (like the older cars).

I think the switch you show in your picture is a warning switch.

Edited my post...

That's what I meant.. .the one that flashes nice and red when your brake pressure is low

Im living dangerously, and have decided to live without that switch