That must be a dummy gauge, so all it tells you is you have at least the pressure the switch is calibrated for. Generally, a real gauge run lower pressure at idle and higher at road speed. With dummy gauges the needle just sits somewhere in the safe zone. Wife's '92 Aerostar with this dummy gauge reads in the N and O range on "NORMAL." Variations in needle location probably due to electrical resistance differences between different gauges.
Can jump the resistor on back of gauge panel, add a real sender, and gauge will be real, but not numbers.
As I recall Ford calls it a switch for the dummy gauge and a sender for a real gauge. I've heard that the switch triggers a gauge reading at a fairly low pressure, maybe less than 10 psi. Also I was told the switch is maybe one inch wide, where sender is about twice as wide, but I had a 90 Ford with the fat sender and a "NORMAL" type gauge. Seemed like a dummy to me. I put in a mech gauge and its needle fluctuated.
Anyway, unless the engine is making noises suggesting poor oil pressure, I wouldn't worry about it. A real gauge is nice though. I'd go aftermarket, AutoGauge by Autometer is nice, but a cheap Sun gauge for $17 will do the trick.