TO select the right fire extinguisher, you must match the extinguisher type with the specific Class of Fire it is designed to fight. Using the wrong type (like water on an oil fire) can be extremely dangerous. Home/Small Office: An ABC Dry Powder extinguisher is usually the most versatile choice.For Sensitive Electronics: Use CO2 to avoid the messy residue left by dry powder.Never Use Water On: Electrical fires (shock risk) or oil/grease fires (can cause an explosion)