1996 Other Oldsmobile Models oil level sensor 3100 engine

Check oil lite same on, oil was ok. Changed oil pressure switch, changed oil and filter. Ran car about 10 miles normally- no lite. Next morning lite on. Checked haynes manual, check oil lite is wired to an oil level sensor in the oil pan not the pressure switch. Where the halibut is the oil level sensor located? Manual doesn't mention it. If I can find it- I can replace it