a small fire that is at the outlet
Unplug it from a distance and then throw tons of baking soda or flour on it until the fire is smothered.
CUT THE ELECTRIC SOURCE OFF BREAKER MAIN POWER SWITCH THEN USE WATER .OR CALL THE FIRE DEPT.
Turn off the power if possible. Electrical fires can be put out with water, if you do not have a dry chemical to use to smother the flame. Electrical equipment will eventually deenergize itself when the conduction material burns through to the point of non-conductivity. The problem with electrical fires is that they spread to the surrounding materials. When those surrounding materials are flammable, that is the real concern.
Shut off power at the circuit breaker and the class 'C' (electrical) fire is out. If anything is still burning, it is a Class 'A' (leaves an ash) fire and water will suffice. Baking soda can be used for Class 'B' (burning liquid) fires, but not electrical fires.