Could be a movie or an episode to a TV show (what I remember reminds me a lot of Goosebumps or AYAotD)
From what I recall, it has a young adult male driving somewhere in the middle of the night (with a younger brother maybe?) and he's falling asleep at the wheel and likely was drifting into oncoming traffic, so he stops in a town and gets a motel room. At some point he takes a pocket knife and stabs the wall and green ooze comes out like the wall is bleeding.
Might not even be a children's genre, I just remember watching it as a kid.