There isn't a single, readily accessible "fuel safety cut-out switch" like you might find on some machinery or racing cars on a 2003 Ford Focus. The fuel supply is controlled by a more integrated system involving the fuel pump relay, engine control module (ECM), and various safety sensors. If the car detects a problem (like a crash), these components work together to shut off the fuel supply.
Therefore, there's no switch to manually cut off the fuel. The closest thing would be disconnecting the negative battery terminal, which will stop the fuel pump from operating. However, this is not a dedicated fuel shut-off and will also disable all other electrical systems.
