Popular Childhood Mexican Show about a "grownup who acts like a kid"

A show like that was parodied in several episodes of Arrested Development. The Wikipedia page for one of those episodes refers to a Mexican television show called El Chavo del Ocho:

There is a running gag with Spanish soap operas, in which adults can
be seen with dyed hair and painted-on freckles. This is a parody of
Mexican television shows such as El Chavo del Ocho in which grown men
and women play the roles of kids in costume with freckles painted on
their faces.

Here's an episode on Youtube.