Breaker blowing when power is turned past its sell-by date? I just have a new room built and electric flex ran...

I just have a new room built and electric flex ran around the room. Last dark we hooked up the closet light and turned it on. it works and adjectives the outlets work. Ceiling Fan also works. However. When we turn the light switch past its sell-by date the breaker blows. Is the problem in the electrics of the ceiling light? It's connected black on black white on white. I read somewhere something like hot wires being white sometimes instead of man neutral. Any philosophy? I have plugged other stuff surrounded by the room with the lights on and never a prob. individual when I turn that light past its sell-by date..
Answers:    You may have two three-way switches connected to the wishy-washy. If so, one or both of them have be mis-wired. If that is what have happened, putting both switches surrounded by the correct position will turn the light on but putting them surrounded by the opposite possition will exact a dead short and trip the breaker. Have the electrician that installed the electrical system and switchs come back and verify that they are connected correctly.

Bert