I woke up in the middle of the night whenever I was really young and there was this marathon of this TV show from maybe the 90s 80s or 70s era. I think it was about an alien posing as a boy on earth to learn about humans and their behavior. I think he kept in contact with his home planet through talking to a screen or something and there was a male voice that answered back. I think the show was setup to teach kids about different things like hygiene and exercise. I remember one episode was about germs and how you couldn't see them and I think there was a song going "We're germs! we're germs!" And in one episode the boy is invited to spend the night at a friend's house. The friend's mother calls to make sure its okay with his parents and the alien boy has the voice from screen to pretend to be his dad and say its okay and the mother tells the voice not to forget that he packs his toothbrush and the voice is like "What's a toothbrush?" Can't remember or find it anywhere and I haven't found it after +15 years. Any help would be obliged.