Which of the following is a common cause of electrical fires?

Overloaded circuits are a well-known and significant cause of electrical fires. This occurs when too many devices are connected to a single circuit, exceeding its capacity to handle the electrical load. When a circuit is overloaded, it generates excess heat, which can cause wiring insulation to deteriorate or ignite, leading to a fire hazard.

In contrast, cold weather may increase electricity demand but is not a direct cause of electrical fires. Low humidity and high insulation ratings, while important factors in overall electrical system performance and safety, do not directly contribute to the risk of electrical fires. Maintaining proper load on circuits is critical for fire prevention and overall electrical safety.