There are a few things that can cause the interior lights to stay on after you've turned off your vehicle and gotten out:
Dome light override switch: Many vehicles have a dome light override switch that allows you to keep the interior lights on even after you've turned off the vehicle. This switch is usually located near the dome light itself.
Faulty door switch: The door switch tells the vehicle when the door is open or closed. If the door switch is faulty, it may not send the correct signal to the vehicle, which can cause the interior lights to stay on.
Faulty light timer: The light timer controls how long the interior lights stay on after you've turned off the vehicle. If the light timer is faulty, it may not turn off the lights after the set time.
Bad wiring: Faulty wiring can also cause the interior lights to stay on. This is a more complex problem to diagnose and should be done by a qualified mechanic.
If you're not sure what the cause of the problem is, the best idea is to take your vehicle to a qualified mechanic to have it diagnosed.