Problems with my lights on my Cadillac deville

I left in my car and the interior lights
stayed on while I was driving then
when I got back shut the car off the
interior lights stayed on for about 15
minutes to tell lights stayed on would
not go off after checking the doors
they still did not go off until the battery
was dead. It did it all of a sudden with
no idiot lights or warnings. While the
interior lights were on  they were
flickering.