The light went out in our refrigerator so I went out to get a new one - thinking it was a simple switch - put in the new one and still no light - it went on for a brief second after I screwed it in and out a few times - it is the light on top - under freezer compartment

Could it be loose wires or something else?

Have you checked the socket the light goes in? Could also be the door switch. Try pushing in and out on the switch to see that its getting good contact