When I'm in an adjacent room to the bathroom and someone flips the switch to turn off the bathroom exhaust fan, I hear a popping noise. I never hear it while in the bathroom flipping the switch - only when in a different room. And I don't hear it when the fan is being switched on - only off. Is the popping noise something I should be concerned about? Thanks.

When a standard switch wall is activated there usually is a snap sound. If you are concerned you might take the switch loose and inspect of any areas for burning of wire insulation (usually indicates over heat condition) and also check the wires for tightness. Turn off power first to be safe.

Where does the poping sound like its coming from? Does it sound like it is coming from the ceiling? Could it be the flapper in the fan vent closing? The noise of the fan may be masking it in the bathroom itself.

Check for a loose connection.