I believe it was a compilation of stories from various authors, and I believe it was a series of multiple books. I am usually a very good Googler but so far have come up empty.
Some stories I remember:
1.) A creepy neighbor in a trash-filled house whose fat stomach has an evil mouth in it. (I believe he may also have collected faces.)
2.) A bored child agrees to trade bodies with a cat and it turns out maybe all cats are kids who have been tricked this way. Eventually he convinces another child to switch with him and is thankful to join that other child's family.
3.) A boy who goes into the scary space under his bed and is forced to become a goblin and kidnap other children to become goblins but misses his family and visits.
4.) The moonlight plays on a girl's wall in some magical way and entices her to leave her family to live on the moon forever.
I would be so grateful if this rings a bell with anyone!