The Whole Town Lives in My Apartment/NPCs in Apartment?

[obamalexis]

I was having some issues with NPCs in my apartment. I downloaded this custom house and it only had a floor for my sim. Because of the random intruders, I wanted to add some NPC doors to stop the issue. I clicked on the callbox and it is filled completely. I'm pretty sure the whole town was listed in it.

How do I fix both issues?