Looking for an old tv show featuring tiny caricature red haired boy with human blond girl [closed]

I don't remember well the date, I guess it would be late 80's and early 90's. The show was about a tiny caricature boy who had wild red hair and a blue overall. He was very naughty and got in trouble a lot. He was a caricature but the rest of the show was played by actors. there was a girl with blond hair and an old man who was her grandparent.

I remember two scenes, one, where the girl was in school and after break she had art class, but the tiny caricature boy got inside the classroom and used the art supplies.

Another one in which the girl put glue around the boy's tiny wooden bed to caught him. I think the boy could make himself invisible if he liked and the girl wanted to catch him. I remember the show being in Spanish, but I don't know if it was a translated version or if it was the original. Can't remember the boys name, but he was very peculiar looking, with fluffy red hair.