OK. So I had a kitchen ceiling light. too big. Took it out and put in a light w/ enclosed fan. Light worked on a single switch. No biggie, light/fan comes w/ remote. Excellent. New light works on same single switch, but it's pretty faint and dims in and out. I decide I want to remove dimmer switch and put in a regular switch, hoping that fixes the strange dimming. NOTE: Light and fan are working w/ dimmer switch, just not excellently. I put in new switch. NOTHING. No power going to light or fan.
In switch box: three white wires connected and wire capped together (dead end.) Three ground wires, connected and wire capped together (dead ended). Red wire. Black wire. Red and black wires are connected to the dimmer switch. I take out dimmer switch, put in single pole switch - nothing. Change out toggle switch for a three-way toggle. Still nothing.
I undo white and ground pigtails and attach a white and a ground to a three-way. I lose power to the entire circuit this switch is on (as in, I flipped the switch in the circuit board and got nothing on anything). I put the wiring back - everything works again. Phew.
Why on earth can't I just replace the dimmer? I've not gotten the meter out yet, as I know there is a functioning circuit. The dimmer switch works.
Oh, and I got a new one-way toggle switch (guy at lowe's thought it might be the switch). Still nothing.