So I took off a broken chandelier and wanted to replace with a simple flush ceiling light. When doing so, I found two black and two white connected properly, but found a lone white wire that was covered by a twist-on. What would this be for? The chandelier never worked after I moved in so I'm not sure. Also, note that the fixture was connected to a rotary knob (dimmer).
Anyway, I wasn't sure what it was for so I attached the lone white to the other two. Now when I turn on the breaker it trips. What would it be for? Thanks!