I'd like to have a light switch that turns on for at most 1 hour. My idea is to put a USB charger (110AC -> 5DC) + arduino + relay inside the wall. When the switch is turned on, it will turn the arduino, which should be programmed to close the relay, sleep 1 hour, open the relay.
Then I'd need to turn off/on to restart the arduino or just optionally turn off in order to save power.
But I feel this solution is a bit overkill (and not too nice). Maybe a physical button that turns off (using a spring?) after a timer? I couldn't find it; or some other suggestion?
Oh, and it would be nice if the solution doesn't have a high probability of setting my house on fire.