What is one key sign of an electrical short circuit?

A sudden increase in current flow and potential overheating is a key indication of an electrical short circuit. When an electrical short occurs, it creates a pathway of low resistance, allowing excessive amounts of current to flow through the circuit. This increase in current can lead to components overheating due to the rapid energy build-up, which may cause damage to the components or even result in a fire hazard. Recognizing this sign is crucial for prompt action to mitigate risks associated with electrical shorts, thereby enhancing safety in handling electrical systems.

The other options do not accurately reflect the immediate signs of a short circuit. Flashing lights may occur for various reasons and are not solely indicative of a short. A consistent humming noise typically suggests normal operation or a fault that needs investigation but is not a direct sign of a short circuit. Electrical components cooling down would indicate a reduction in current flow, which is contrary to the behavior observed during a short circuit.