I have a switch loop that provides power to another room. I recently installed a ceiling light in the room with the switch loop. That light works off a single toggle switch. The other room has a ceiling fan with a dimmer switch. When I turn on the dimmer switch, the light comes on in the other room, even when the wall switch is in the off position. Donf or Donp helped me solve the last problem. Care to help again. However, I'll accept advise from any of smart folks out there.

Switch loops do NOT provide power. They have a sole purpose of energizing or de-energizing a circuit. Switch loops do not have a neutral. What you did is tap into the feed from the other circuit. It's a simple matter of rewiring.