Rosa - I think what you experienced is a homeless townie situation. There are very specific townies that live in households but nowhere especially in the beginning of a file. Those people are usually named on the wiki. They're the people who get jobs like Tattoo artist within the town. The longer you play the more all of them just lump into one household instead of several but yes, watching them go home can be very helpful. Also double-checking each house in a "Copy" of the file that you don't play.
I have experienced those before. Like Shana Natcher in Riverview and Milton Tong in Sunset Valley. Regan Albert and her husband (yes, I broke them up) are not listed on the Wiki for Moonlight Falls. I am far past the beginning of the file (Week 28). She joined the Music career, probably the same time my spare did so he would have co-workers, like Chris Steel does in Sunset Valley. She seems like a new townie family that moved to town later in the file, especially since she has a husband, but for the small detail that she doesn't live anywhere.
Her husband was not listed in her household when I checked (after I broke them up). Do you think it's possible she used to live in a house and then when I broke them up she moved? I would be surprised, especially since broken-up couples live together for a long time in my experience, which I find unrealistic. But then my Dynasty copy of Moonlight Falls has been particularly crazy. The Durwoods (minus Zack) moved out of town right after he moved in with Marjorie. Maybe they didn't approve of the match? And townies have been moving into all different houses like a giant game of musical chairs, producing the oddest combinations. This started happening fairly early in the file.
Anyway, I'm sorry for the long post, I know it doesn't really matter, but I am curious, especially since I had to break the poor boy up with Regan and he was so in love with her.