*batteries not included

By Wayland Drew (based on a screenplay)

An old apartment building is in danger of being torn down by a developer, which it might not be if the building is fixed up and shown to be of some historical value to the city. But the tenants have run out of time and have no money and the developer has sent some thugs to persuade the holdouts to move. One of the tenants sends out a desperate prayer for some kind of help and the prayer is heard and two miniature flying saucers show up. These saucers, which seem to be a male and female, like things nice and neat and clean and they soon get the place looking spic and span, including one of the tenants' cafe in the first floor of the building. Soon the cafe is doing a good business and the thugs, dismayed to see these holdouts prospering, bust up the cafe and break out its windows.
But the little saucers, joined my their tiny offspring, are up to the task and they get the cafe repaired overnight. What the thugs do next just may be the end for the people of the old apartment building and of the little flying saucers.

I think this book is basically meant for children, such an unlikely story and a pretty simple plot. I never saw the movie it was based on, so I don't know if the movie was any good. The book was an OK read, but pretty juvenile.