What was found
BLI FLIGHT 2158 ON SHORT FINAL, MASTER WARN NR 2 ENGINE OIL PRESSURE CAME ON. RAN CHECKLIST, LIGHT WENT OUT AFTER 5 SECONDS. OIL PRESSURE GAUGE READING NORMAL, IN GREEN ARC. FOUND OIL CONTAMINATION IN NR 2 OIL ENGINE OIL PRESSURE SWITCH CONNECTOR. CLEANED CONNECTOR. GROUND RAN AIRCRAFT AT VARIOUS POWER/CONDITION LEVER SETTING. NR 2 OIL PRESSURE NORMAL. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.