The answer to 'how long does switch last' is that the average lifespan of an electrical switch is 10-20 years with normal use. Switches are designed to withstand thousands of on/off cycles, but their longevity can be affected by factors like the switch's quality, how often it's used, and environmental conditions.
Higher-quality toggle, rocker, and dimmer switches tend to last longer than cheaper models. Switches that are frequently used, such as in high-traffic areas, may wear out sooner than those used less often. Switches exposed to moisture, heat, or other harsh conditions may also have a shorter lifespan.