* Under the dash: This is a common place for aftermarket switches to be mounted. Check near the fuse box or other electrical components.
* In the engine compartment: Less common, but possible. Look near the fuel pump relay or other related components.
* Under the hood, near the battery: Another less likely, but possible spot.
If you're having fuel delivery problems, the problem is more likely to be the fuel pump itself, the fuel pump relay, a clogged fuel filter, or an issue within the fuel system rather than a deliberately installed cut-off switch.