I have one experience with a high oil pressure problem, in 1997.
My car at the time was a 1995 Tempo 55K miles. After the oil filter blew off from high oil pressure, I removed the oil pan, and then the oil pump. I found a small piece of plastic stuck in the oil pressure regulator valve.The valve was stuck open. I removed the plastic debris and the oil filter never blew off again.
Currently on my 1987 Toyota Corolla, my oil indicates high when the switch is on and engine not running. I traced the circuit back into the gauges and found a capacitor in the dash panel. I'm going to replace it, and see if the oil pressure goes back to normal. I'm thinking it is shorted and storing to much electric current causing the gage to read high. My fuse was blown too.