You have an electrical fire in the cockpit...
As your first action, do you:
- Declare an emergency?
- Turn off the master switch?
My initial instict was to immediately turn off the master. However, I then thought that maybe you want to send a mayday as this is a serious problem, and this may be your only chance to communicate; once the master is off, you don't want to turn it on again...does this warrant a change in "Aviate, Navigate, Communicate"?
I discounted option 3, "Turn off the fuel valve", as just making a bad situation worse.