So where is the oil pressure cut off switch located on 95 caprice classic

SOURCE: cutting off while driving

Try checking fuel pressure again with a guage on the fuel rail. If you still notice the pressure is low and you know the fuel pump is good, the fuel pressure regulator may be bad. Sometimes you can tell by unplugging the vacuum hose from it and if you see gas that means the diaphram is leaking. If everything checks out with the fuel system a bad EGR valve or EGR valve solenoid can cause cars to sort of stall under half throttle. Good luck and keep me posted. If you found this helpful please rate this solution.

Thanks - Tech101

SOURCE: oil pressure sensor location

drivers side right above the oil pan

SOURCE: Volvo 850 oil pressure sending unit

It's on the engine, right next to the starter, it has one wire going to it. You don't need to drain the oil. If the light is coming on, you may have bad seals in the oil pan, a fairly common problem, but replacing the switch is a good fisrt step.

SOURCE: Leaking oil from oil pressure switch

I've seen pressure switches rust out and shoot a steady steam of oil out of them, so yes it could cause you to loose two quarts of oil. Book does not mention starter removal:
REMOVAL & INSTALLATION

1. Disconnect the negative battery cable
2. Raise and safely support the vehicle.
3. Drain the engine oil.
4. Disconnect the switch electrical lead and unscrew the switch. To install:
   
5. Coat the first two or three threads with sealer. Install the switch and tighten until snug.
6. Attach the electrical lead.
7. Lower the vehicle.
8. Connect the battery cable and fill the engine with oil.

SOURCE: location of oil pressure switch.

how change oil pressure sensor in 2001 mazda mpv dx