The chances of a real oil pressure problem are virtually nil. You have either a oil pressure sender problem or a lower engine wiring harness problem. The next step is to inspect the wiring that goes to the sending unit. If it's bad, i.e. crumbling and bare, you need to either replace or rebuild the harness. If the harness looks good just replace the sending unit, not very expensive and easy to replace.

PS - the sending unit is at the base of the oil filter housing.