After driving my 2003 chevy Impala for about a half hour or so my dome lights in the back seat and the lights on the mirror come on and then slowly fade out but then they keep coming on and fading back out the longer i drive it after they come on and fade out they come on quicker like right after the light fades it comes right back on

Check vehicle recalls at the AutoZone web site for your vehicle. I found the below information there and could be the cause of several peoples issues with lights and cars not starting. 1995-1999 Chevy passenger cars;" These vehicles have the potential to experience moisture entering the Powertrain Control Module (PCM), as a result of corrosion after extended exposure to road salt, Moisture entering the PCM can lead to symptoms including illumination of the Check Engine light or the engine running rough. If these symptoms are ignored, the engine may stall and may not be able to be restarted".

Sounds like a bcm (body control module) could have a short take the positive wire off the battery post and us a test probe use the clip end on the cable and the probe end on the positive post if the light comes on you have a short start removing the Under hood fuses and when the light goes off you'll know what has a short

its a bad door switch or a door is not closing all the way.