1. The ignition switch is faulty and allowing power to flow to the starter even when the key is turned off.
2. The starter solenoid is stuck in the engaged position, causing the starter to continue cranking.
3. There is a short in the wiring between the ignition switch and the starter, which is allowing power to flow to the starter even when the key is turned off.
To diagnose the problem, you will need to check the ignition switch, starter solenoid, and wiring. If you are not comfortable with electrical work, it is best to have the car towed to a mechanic for diagnosis and repair.
