well, it could be the oil pressure switch. Generally speaking low oil pressure is due to excessive wear inside your engine, unless the pressure sender, wiring or gauge is faulty, the only way to fix this problem is to replace or rebuild the engine.
Oil pressure is an important factor in the longevity of most internal combustion engines. Sufficient oil pressure ensures that the metal of the rotating shaft and the bearing shell can never touch, and wear is therefore confined to initial start-up and shutdown. Excessive oil pressure may indicate a blocked filter, blocked oil gallery or the wrong grade of oil which results to possible mechanical problems. So that is why we need to regulate the oil flow and pressure in our vehicle so that all engine parts get the right amount of oil. In order to monitor oil pressure, we need an oil pressure regulator.
When i had this problem with my engine, i ended up buying the
AC Delco Oil Pressure Switch. It helps me a lot because the switch triggers the light to blink reminding me that oil pressure goes below the set level and need to fix it asap. It really saved me from irreversible damage.