I have a project that turns a LED strip on and off using capacitive touch. The project uses an Arduino Micro as the brain and a 12v wall wart to power everything. I have the Arduino ground and negative from the power supply running to a common ground.
Everything works as expected during testing and the Arduino is connected via USB to my computer; however, when I unplug the USB and connect the circuit to the light installation, the lights just flicker on and off. When I touch my finger to the negative/ground (and presumably provide common ground), everything works as expected.
It seems obvious to me that I have a grounding issue, but really do not know how to proceed. Is there a specific technique for grounding from a wall wart? Do I need to somehow pull the ground/negative down? I feel like there is something obvious that I am missing.
Thank you in advance for any and all help.