Light switches exemplify familiar design, which, according to Henry Petroski’s Small Things Considered: Why There Is No Perfect Design, is a name for things that are “so predictable in their form and function that we do not give them a second thought.” We haven’t given light switches much thought for nearly a century now. The toggle light switch was patented in 1917, replacing the push-button switch of the late 19th century. Since the toggle’s inception, it has remained the most ubiquitous switch in North America. The 1980s saw the introduction of the rocker, a flat-paneled switch that became popular domestically and throughout Europe and Asia. But the rocker was really just a facelift, a minor aesthetic evolution of the traditional design similar to the shift from push-button to toggle. The light switch has essentially never changed.