What is the effect of using insufficient gauge wires in a circuit?

The use of insufficient gauge wires in a circuit can lead to overheating due to their inability to safely carry the electrical current required by the connected devices. Wires are designed to handle specific current levels based on their gauge; thicker wires (lower gauge numbers) can carry more current without overheating, while thinner wires (higher gauge numbers) have a lower capacity. When current exceeds the safe limit of a wire, the resistance in the wire generates excess heat. This can not only damage the wire itself but also create a fire hazard. Therefore, using wires that are not appropriately sized for the circuit's current demand can significantly increase the risk of overheating and other electrical failures.