Final answer:
Using water to put out an electrical fire is not acceptable due to the risk of electricity conduction. A Class C fire extinguisher, sand, or a proper fire blanket are the appropriate methods to address such fires.
Step-by-step explanation:
The method that is not acceptable for putting out an electrical fire is water. Using water can be dangerous as it conducts electricity, which could potentially spread the fire or lead to electrocution. Instead, a Class C fire extinguisher is effective for electrical fires as it contains non-conductive substances. Sand and a fire blanket can also be used to smother the fire and cut off the oxygen supply. However, when using a fire blanket, ensure it is the right type for an electrical fire.