How does it let you know when the timer is almost done? Does a light come on the switch or does it flash the light on and off in the room? Or a alarm?

The RT2 is a time switch that turns OFF the connected light or fan when the selected time expires. An indicator light illuminates when the switch is OFF. When selecting a time delay of 20 min or more, as time expires, the button LED’s will move through the next available time delay, always giving an indication of the amount of time left before the time delay expires. One minute before each time delay transition, the active button LED will flash, providing the user an indication of the transition.