The answer to 'why is my dimmer switch flickering lights' is that a flickering or flashing light is a common symptom of a problem with the dimmer switch. This can be caused by a variety of issues, such as a loose connection, a worn-out switch, or compatibility problems between the dimmer and the light bulb.
If the flickering is intermittent or only occurs when the lights are dimmed, it's likely a problem with the dimmer switch itself. This could be due to a loose connection, a worn-out switch mechanism, or compatibility issues with the type of light bulb you're using. In some cases, the dimmer switch may simply be reaching the end of its lifespan and needs to be replaced.