The door switch for the VW Polo can go bad and cause the interior light to stay on. The switch must be changed, there is no way to repair it.
One of the door switches could be stuck. Or the interior light switch could be going bad. See if the open door light is staying on, of if the interior light switch seems stuck or loose.
inside the door panel
The interior door switch may be built into the door latch. It is on the 2001 Ford F-150.
in the locking mechanism
On the catch
On the interior lights for the back seats, there is a switch. When you turn the switch to "Door" mode it will make the lights turn on when the door is opened.
Interior light for astra mk3 not coming on when door opened or headlight switch pulled.
You may have the main switch turned on for the light. If the main switch is on, closing the door will not result in the light going off.
If your interior light is also on, replace the door switch.
The door switch is coroded or broken.
Could be the interior light switch on the dash is turned on or the door light switch is broken.