Hue light switches (well, the ones I have) simply stick on the wall with no wiring.
The _real_ light switch is permanently on, and the _hue_ light switch sends a beacon to the hub to turn the configured lights on/off (the light bulb socket is always-on)
No, some switchers and dimmers can also control lights without a hub present. Some products come as a paired bulb and switch, with only an optional suggestion that you later extend into the ecosystem.
The _real_ light switch is permanently on, and the _hue_ light switch sends a beacon to the hub to turn the configured lights on/off (the light bulb socket is always-on)