I did a bit of reading up on the topic, bought myself a tester and so on. I was expecting to find a white wire and a black wire. However...when I took off the existing fixture (nothing more than a simple piece of metal with a bulb), I noticed that there was a white wire coming down from the ceiling that was twisted on to the white wire belonging to the fixture (expected), however..instead of a black wire attached to the fixture, there was a single red wire coming down from the ceiling and screwed into the fixture itself (no 2nd red wire).
There was a black wire however....it just was not being used.
In any case, I attached the new fixture, connected the white to the white again, and figured to continue using the red.. I attached the red from the ceiling (since it was attached to the previous fixture) to the black wire in the new fixture.
Put everything back on...and presto, it worked fine. However....around half an hour afterwards, the breaker shut itself off!!
Am I doing anything wrong? Should I have attached the black wire (previously unused with the first fixture) to the black wire on the new fixture? And if so...what about the red wire that was attached to the first one? What is the reason that the breaker shut itself off?
Any help would be GREATLY appreciated.