To find it definitively, you'll need to:
1. Consult a repair manual: A Haynes or Chilton repair manual specific to your 2001 F-150 V6 will have a diagram showing the exact location. This is the most reliable method.
2. Use an online parts diagram: Many auto parts websites (like AutoZone, Advance Auto Parts, etc.) allow you to look up parts diagrams for your specific vehicle year, make, model, and engine. Find your engine's diagram and locate the oil pressure switch.
3. Visually inspect the engine: With the engine cool and the oil cap removed, carefully look around the oil filter area on the driver's side of the engine. The switch is usually a small, cylindrical component with one or two wires connected to it. Be cautious not to burn yourself on hot engine parts.
Remember to always disconnect the negative battery terminal before working on any electrical components in your vehicle.