That was me. *guilty*
Actually, after a much-needed shower after all that cleaning, I went out for a smoke, and I guess the wind must've been blowing in the wrong direction or something, because the smoke alarm started beeping like a mad something-or-other.
As soon as I put the cigarette down and went to go inside, it stopped. *shrug* That never happens, though... But there have been a few occasions where the smoke alarm has gone off randomly, and briefly, for no reason. So it might've been that.