•the space is so small that the exit is easily within reach. Storage rooms and janitor closets are typical applications.
•the space has adequate emergency lighting. For example, you can use timer switches to provide lighting for cleaning crews who work in large office spaces late at night. The timer switch overrides a time clock or key switch that is used to turn off the lights after hours. The emergency lighting is bright enough to provide safe access to the timer switch.
•a minimum lighting level is provided by adjacent lighted spaces. For example, you could safely use timed-turnoff switches for individual stacks in a library, or for individual stock shelves in a warehouse, where individual areas are used only occasionally and for short periods. Even here, timer switches would be unsatisfactory if the lighted spaces are visited
frequently. Exploiting this kind of opportunity is likely to need light circuit modifications and installing the switches in unconventional locations, such as from overhead fixtures.