How do you wire a 3 switch box in a bathroom?
1 white which is hot, and 2 greys which are hot...the switch is on 2 seperate breakers.


This means that:


  new switch it only has 1 common hook up, then 3 other connectors on the otherside.


The new switch will NOT work here.

You cannot feed from "2 separate breakers" to "1 common hookup" - you need a different switch that more closely matches the old switches (which look to be 3 separate switches, each with its own connections.)