The answer to 'when to replace light fixture' is that you should replace a light fixture when it is no longer functioning properly or if it is outdated and no longer fits your home's style. Light fixtures typically last 8-15 years with normal use, but can fail sooner if they are exposed to moisture, vibration, or other environmental factors.
Some common signs that it's time to replace a light fixture include flickering lights, dimming, buzzing or humming noises, or if the fixture is cracked or damaged. Additionally, if the fixture is no longer compatible with modern lighting technology like LED bulbs, it may be time for an upgrade. When replacing a fixture, it's important to choose one that is the correct size and style for the space, and to have a licensed electrician install it to ensure safety.