The properties of hallway switches are discussed with emphasis on how special types of such switch systems with arbitrarily many switches can be constructed and systematically become conducting/nonconducting by simply turning on/off any arbitrary switch in the system, and then become nonconducting/conducting again by turning off/on any arbitrary switch in the system, etc. A question is whether in physics, biology, genetics, economics, sociology, or traffic management, there might exist - or preferably would exist - complex such systems, the global state of which could thus be switched by a local action anywhere in the system and then switched back by another local action anywhere in the system.

arbitrarily large switch systems, on/off activation at arbitrary switch, applications searched