There isn't a readily accessible, easily identifiable "fuel cut-off switch" like you might find on some larger vehicles or machinery in a 1996 Ford Mondeo. Fuel delivery is controlled electronically, and disabling it would require disconnecting the fuel pump (which is not a simple task and should only be done by someone familiar with automotive systems) or potentially by disabling the fuel pump relay.
To reiterate: There is no readily accessible switch. Attempting to find or install one yourself is highly discouraged and could be dangerous.
If you need to disable the fuel supply for safety or maintenance reasons, you should consult a repair manual or a qualified mechanic. They can safely disconnect the fuel system components.
