How we cite our quotes: line
Quote #1
I have gone out, a possessed witch,
haunting the black air, braver at night; (1-2)
Why might our speaker be braver at night? We get the sense that she enjoys being outside of the hustle and bustle of everyday life. It's when she's alone that she can allow her real identity to come out.
Quote #2
dreaming evil, I have done my hitch
over the plain houses, (3-4)
Notice how there don't seem to be any fellow witches in this picture? Our speaker's out there on her own, above all the houses where everyone else is doing their living. Describing the houses as "plain" suggests that they're both normal and, well, boring.