Zookie,
I must agree that trying to clear another's space was an intrusion even if done with good intention. Unfortunately we live, we learn, and good thing, keep on going with our gathered knowledge. Perhaps that nasty thing you saw was just your own higher self saying "stop, your crossing aline".
I do hope your own place feels nice and clean, a good idea to do everyso often when one does energy work.
Live, love, laugh,
Tracey