Oil pressure low at an idle

I have good oil pressure when it's cool but the warmer it gets the lower the pressure goes down to about 10 or 12 oz is that normal

Are using recommended oil or have high miles?

You have no information so< where do you live? Have you replaced warm weather oil for a lighter weight winter blend? Several people with similar issues found there is a filter inside the engine that requires the oil pan to be pulled. It has to be manually cleared of gunk. Your car is now middle age and that may be the issue. If it is cold out, perhaps the oil is not warmed up yet, as it does take awhile in very cold weather to warm up. Are you using the artificial oil? Perhaps upping to a thicker blend may help also. It may be a sensor, but from what you say, it is not too likely, but do not rule that out either. At normal road speed, 2,000 to 3500 rpm, what is the pressure, and does it fluctuate? Just on a whim, check the oil level.