The answer to 'dimmer switch making buzzing noise' is that a buzzing or humming noise from a dimmer switch is a common issue and can be caused by several factors. The most common causes are an incompatible light bulb, a loose connection, or a faulty dimmer switch.
If the dimmer switch is making a buzzing noise, first try replacing the light bulb with one that is specifically designed for use with dimmer switches. Incompatible bulbs can cause the dimmer to buzz. If the noise persists, check the wiring connections at the dimmer switch to ensure they are tight and secure. If the connections look good, the issue may be with the dimmer switch itself, which will likely need to be replaced by a professional electrician.