Oil pressure in a 95 dodge dakota

In my 95 mag6 my oil pressure gague reads high almost takct’n out, how ever in the morning on cold temp it reads dangerly high, when it sets and the temp outside is very warm it will read normal to a little high. When I stop it goes to 50% to 45%. Is this my oil gauge acting up or a pvc valve or something more serious. It has 124000 miles on her.