I have three switches in a box. One controls the light on the ceiling fan and one controls the ceiling fan. I cannot figure out what the third switch is used for.
I thought it might have controlled switched receptacles. However after testing all receptacles in the room with the mystery switch on and off, I saw no change in power being supplied to the receptacles. I used an receptacle tester that plugs into the receptacle. I tried both the top and bottom outlets in each receptacle.
Does anyone have thoughts as to what this switch could control? How can I identify what the switch is used for?
A picture of the switch box:
UPDATE: As @Edwin guessed, this switch was previously used for two switched electrical receptacles. One of the switched outlets had been replaced since the house was built and the fin use to make the top outlet switched had not been removed. This caused the outlet to have power regardless of the switch position. I'm guessing this was done when the ceiling fan light was installed and the homeowner no longer wanted the switched outlets. I've replaced the receptacle and now the switch works--switching the top outlet on two receptacles. Mystery solved! Thanks go to everyone that had a suggestion and offered advice.