Uninvited neighbors entering without permission!

Sims with certain traits have a habit of coming over uninvited - IIRC, the traits are Goofball, Erratic, and/or isWeirdo (I don’t remember exactly which). You can use cheats or mods to take away these traits, or just find them in household management and change their traits in CAS (except for isWeirdo, since that’s a hidden NPC trait that can only be seen or removed using cheats/mods).