The answer to 'why is my dimmer switch dimming lights' is that there are several common causes, including an incompatible light bulb, a problem with the dimmer switch itself, or issues with the electrical wiring. Dimmer switches work by reducing the amount of electricity flowing to the light bulb, which can cause the bulb to appear dimmer. However, if the dimmer is not functioning properly, it may cause the lights to dim unexpectedly or not dim at all.
Some of the most common symptoms include the lights flickering, buzzing, or not dimming as expected. In some cases, the dimmer switch may feel hot to the touch or the lights may suddenly go out completely. The solution will depend on the underlying cause, but it may involve replacing the dimmer switch, upgrading to a compatible light bulb, or addressing issues with the electrical wiring.