Look under the dash on the drivers side at the brake pedal.
There is a brake light switch that has a plunger that comes out when the brake is applied .There is a little rubber piece that is on the bracket for the switch plunger to contact when the pedal isnt applied to turn off the lights.
This rubber stop comes off after time
Stop in at the dealer to get a new one and pop it in.
Temporarily,you can tape a piece of cardboard or a penny in place til you get the correct stopper.
Use the correct stopper,above is only a temp fix
You can pull the fuse if you like while its parked so battery doesnt go dead just put it in before driving