[thstone]

Its worrisome any time that the oil pressure warning light comes on. But I feel better since it came on with the charging system light which leads me to think that it was an electrical problem and not an oil pressure issue. Thus, as others have commented, I'd check the electrical system for any issues - could be anything from the electrical portion of the key switch going bad to a failing alternator/voltage regulator to a bad ground to ... etc, etc. By the way, sometimes a ground cable can corrode from the inside so you may need to measure resistance rather than just visually inspect.

If at any point the oil pressure warning light FLASHES (regardless of any other lights that might turn on), turn off the engine and have it flat bedded to a shop for investigation.