Erratic reading on Digital oil pressure gauge

In the last year I have put on just over 16k miles without a problem. I just did the third oil change last week, using the same oil as before (Mobile 1 Synthetic for engines with higher mileage), same filter, etc. Two days later my digital oil pressure gauge starts going haywire. It normally would range from 65-73 lbs. of pressure consistently. Suddenly its reading all over the place... from 65 to 45 to 0 to 15 to 5 to whatever..... all real fast readings that you can hardly fix your eyes on. then it might cease this erratic behavior altogether and maybe start up again further down the road. I thought for sure it had something to do with the oil or the filter I just installed. I removed both and started over after only 2 days. Another new filter and oil. No change, same issue.
Is this an issue with the oil pressure sending unit or should I prepare for the worst? The engine operates just like usual. No vibrations, no unusual noises, nothing. Sometimes the gauge reads zero pressure for more than 5-10 seconds... still nothing unusual. I should note than this has in no way since it began, ever shut the system down. It continues to run just fine. Since this happens almost daily and the engine has yet to proclaim any deeper issue, I continue to drive it. Now and then it rears its ugly side and declares a pressure problem, with the side effect of setting off that terrible sounding alarm (that same one that says you're almost out of gas). If nothing else, how can I possibly shut off that alarm notice......the nervous tension is going to send my to my grave....

Thanks guys.