Tail Light Switch problems of the 2012 Kia Motor Optima

Issue started 2 months ago. Noticed that vehicle acceleration is sluggish. Sometimes I have to take foot off the acceleration pedal then depress it again in order for vehicle to accelerate. Acceleration is unreliable and dangerous. Electronic stability sensor also started lighting up and cruise control became inoperable. Also noticed that my tail lights lit up on its own (and did not turn off) while vehicle is parked and fob not near vehicle, draining the battery. Police came by in the middle of the night to report that my tail lights were on. Tail light did not turn off when pressing the fob unlock/lock button. Had to restart the engine, drive around the block then turn off engine before the tail lights came off. . . But it turned back on again on its own that same night (in the middle of the night) and had to repeat the process. My battery was drained and had to replace it 3 days ago. I thought it was a battery problem (and was informed by dealer that it was probably a battery related issue) but problem persisted. Read reviews and this seems to be a running complaint with issues on brake pedal stopper or brake sensor stopper. Will bring vehicle to dealer in the morning.