The answer to 'why is my electrical wiring circuit overload' is that your circuit is drawing more electrical current than it is designed to handle. This can be caused by too many devices or appliances being connected to the circuit, a short circuit, or a faulty component in the circuit. Symptoms of an overloaded circuit include flickering lights, frequently tripping circuit breakers, or warm or buzzing outlets.
To fix an overloaded circuit, you should first unplug any unnecessary devices and spread the load across multiple circuits if possible. If the issue persists, you may need to upgrade the circuit by installing a higher-capacity circuit breaker or adding additional circuits. However, this type of electrical work should generally be done by a licensed electrician, as improperly modifying your home's electrical system can be very dangerous.