08 sts 3.6 electrical

Needing help just picked up a 08 sts 3.6. Having an electrical issue. So when anything is opened, moved or pressed in acc or engine completely off the throttle body clicks and sounds like its moving. Another thing is wife pushed hazards button gauges twitched, throttle body does its thing along with other stuff. Radio screen is intermittent. Comes on when ever it wants. New battery and alternator is good. Someone did have a system over the stock bose one tapping into the oe woofer and also had monitors in it at one point tapping into the rear cig lighter. I put everytjjng back to normal