The answer to 'why is my dimmer switch circuit overload' is that the dimmer switch is likely trying to control too many lights or high-wattage bulbs, causing an overload on the circuit. This can happen when the total wattage of the lights connected to the dimmer exceeds the dimmer's capacity, or if the dimmer is old and no longer functioning properly.
Some common symptoms of a dimmer switch circuit overload include flickering or dimming lights, the circuit breaker tripping frequently, and the dimmer switch feeling hot to the touch. To solve this issue, you'll need to reduce the total wattage of the lights on the dimmer circuit or replace the dimmer switch with one that can handle the load.