2002 Chevy Impala Headlights and tail lights flicker, click

Recently I noticed that my headlights and tails lights flicker accompanied by a clicking sound coming from the front passenger side of the car. I can override these symptoms by manually turning on the headlights by pulling the headlight knob on the dashboard. However, if the manual switch is pulled, then I shift the car in reverse, the exterior lights begin flickering immediately along with the clicking sound. The clicking and flickering of the lights seems to be synchronized. The car runs fine with the exception of the issues listed above. What are causing these issues and how can they be addressed?