Buzzing noise from light fixture

Answer 1

A buzzing noise from a standard incandescent lighting fixture can be caused by a short in the lighting circuit (which is dangerous), or in some cases it can happen using a rheostat that is not all the way on or all the way off. The larger the physical size (not necessarily wattage) of the filament, the more likely it is to buzz using a dimmer -- these bulbs are designed for 120 volts, and using a rheostat gives less voltage to the lamp.

A tube fluorescent fixture can make a buzzing noise if the ballast (small electrical box inside the fixture) is beginning to fail.

Some outdoor fixtures are inherently noisy, such as a sodium arc lamp. In this case, there is really nothing to be done about it.

Answer 2

A buzzing noise from a light fixture could be caused by loose wiring, a faulty light bulb, or a magnetic ballast. It is important to turn off the power to the fixture and check for any loose connections or replace the bulb to see if the noise persists. If the issue continues, it may be necessary to replace the ballast or contact a professional electrician for further assistance.