The answer to 'switch replacement schedule' is that most light switches in a home should be replaced every 10-20 years, or when they start showing signs of wear and tear. Light switches are relatively inexpensive and easy to replace, so it's generally recommended to replace them proactively rather than waiting for them to fail completely.
The lifespan of a light switch can vary depending on factors like usage, quality of the switch, and environmental conditions. Switches that control high-traffic areas like hallways or bedrooms may need replacement more frequently than those in low-traffic areas. Additionally, switches that control high-wattage loads, such as those for ceiling lights or heavy-duty appliances, may wear out faster than lower-wattage switches.