How to defuse an electrical fire?

"To defuse" implies that you already have an electrical fire. Therefore, you have three options.

1. secure the electrical power to the device that is on fire. Once the power is secured, you no longer have an "electrical" fire. Electrical fires only exist in the presence of electricity. Once the power is secured you may still have a Class Alpha fire due to burning insulation, but the electrical fire ends immediately once power is secured.
2. (if) power can not be secured, then use a class Charlie fire extinguisher to extinguish the fire (if available). This will use CO2 or a dry chemical extinguishing agent to stop the fire. Note: never use water on an electrical fire.
3. (if) power can not be secured AND you do not have a class Charlie fire extinguisher, you can use Baking Soda (Sodium Bicarbonate) to extinguish the fire. This is the same chemical in Class charlie dry chemical fire extinguishers.

-Cheers

First Comes safety.

First of all we have to cut the Main Power.

second we have to secure the parameters.

third Evacuate the Place so we can face no casualties

fourth remove any fire catching material like Gasoline etc etc.

fifth if the automated fire extinguishing system could not turn on. then immediately call the safety department.

if the fire is on the small scale then you must take a fire extinguisher clinched to the wall and use to extinguishes the fire

By deactivating the main power supply point to prevent from explotion

1.  Using Electrical Appliances and Equipment Safely by:

• Avoid overloading outlets. Plug only one high-wattage appliance into each receptacle outlet at a time.
• Disconnect small appliances when not in use.
• Following the manufacturer's instructions for plugging an appliance into a receptacle outlet.
• Make sure your home has ground fault circuit interrupters (GFCIs) in the kitchen, bathroom(s), laundry, basement, and outdoor areas.

2.  Maintaining Electrical Plugs, Outlets, and Cords

• Make sure all electrical outlets are fitted and tight to the wall.
• Do not tamper with electrical plugs. 
• Use a surge protector for multiple plugs.

3.  Maintaining the Electrical Wiring in Your Space

• Get the electrical wiring checked by a qualified electrician
• Update the electrical wiring every ten years
• Replace damaged or loose electrical cords.
• Avoid running extension cords across doorways or under carpets.

there are followings setup to defuse the electrical fire.

Verify that outlets and extension cords are not overloaded.

* Examine electrical cords to ensure they are not frayed, damaged, or placed under rugs or carpets.

* Verify that the proper wattage bulbs are being used in light fixtures and lamps.

* Consider installing ground fault circuit interrupters (GFCI) in bathrooms, utility rooms, and kitchens. This device protects people against electrocution by shutting down the electrical system if it detects any imbalance in the electricity.

* Take steps to safeguard electrical appliances from power surges. A power surge is a sudden rise of current or voltage in an electrical circuit that can last up to several seconds and can ruin electrical appliances and equipment, such as computers. You can purchase surge protection devices to safeguard against the problem.

Install child tamper-resistant electrical outlets to prevent a child from inserting something into the outlet holes.

* Install arc fault circuit interrupters (AFCI) to avoid fires caused by arc faults. An arc fault is a discharge of electric current across a gap.

This can be caused by improper electrical connections, pinched wire insulation, and overheated wires.