The bathroom light switch is located just inside the door. It is an on-off switch if you single-click, or a dimmer if you press-and-hold. It will remember the last dimmer setting when turned off and back on
If the bathroom light is flashing rapidly (rave mode) it has lost its settings. It can be returned to normal operation by turning the light off then using three clicks of the top button in a tap-tap-hold pattern. After holding for a couple of seconds the indicators on the switch will illuminate and the overhead light should return to normal (non-rave) operation