Oil pressure light on 63

[brokestudent]

I am feeling like there is not a huge problem with the truck, but I am new to these so I am wanting to check. I also want to establish I just had my oil changed 5w-30. It was doing this before the oil change too though. When I am driving it runs fine feels good no loud noises etc, but my light of my oil pressure flickers. There does not seem to be a hugely noticeable loss in power, time when it does it, etc. but it does flicker. Is this a huge problem? Is it just a bad sensor or grounded wire? I am good on oil level so I am pretty sure it is not that, and even that being said the oil does not seem to leak like it should for a 51 years old truck.