I've seen more oil pressure sensors go bad then oil pumps. I would check the oil pressure with an oil pressure gauge first off, just to put your mind at ease when the light comes on. Then If the pressure is within spec. i would replace the sensor after checking the circuit out to make sure my wiring wasn't having a problem. I have seen the wire coming from the sensor rub againest the bottom of the intake manifold and ground out causing the same problem.