Windshield Wipers and Power Windows Working Sporadically

I have a problem with my windshield wipers that seems to also affect the power windows. One day they work fine but, you can hear a 'click' sound while the wipers are running and they stop. When you go to roll the windows down (or up) after this happens, the power windows also do not work. However, afterwards (sometimes in the same trip, others, the next time you drive the vehicle) you can hear a click and they start working again. Any idea as to what is going on? Loose cable? Bad relay? Bad control module? Any ideas would help.