Random Sims Enter My House, Cannot Get Them To Leave. June, 2020

@Purrpledrank Below are some thoughts and things that you can try to see if they help:

• If you ever had Mods or CC in the past, please delete the localthumbcache.package file in your 'The Sims 4' folder. 
• You mentioned that you don't have any Mods... do you have any CC?
• What are the lot traits? ( Go to Lot type > Traits Panel )
  
  
  You could click the "X" on one of the current lot traits and a panel will open up to choose a new lot trait. You can choose the 'Private Dwelling' lot trait:
  
• Please experiment with changing the door locks so they only have one lock setting - lock to non-household. This is a 'just in case' measure to test, as there have been times in the past that door locks have been buggy when used for more than one lock type.
• Please check all sims in the household to make sure none of them has a relationship with this Sim. Sometimes that can make them welcome when you didn't realize it.
• Do you have a roommate? Roommates will invite others over autonomously and they will just walk in and make themselves at home.
• Is anyone in the household a celebrity? I've had others just come on in in that situation as well.
• If all else fails, you can hover over that other, intrusive Sim and get their name and hunt them down in 'Household Manager'. If you want to not be nice you can delete the sim &/or their household there. If you want to be nice you can play that Sim long enough to have them leave the lot, plus while you're in there check out their traits and needs to make sure things aren't wonky there.

Let us know how it goes, or if any of this helps. Thanks & good luck! 

1. I have never used a mod, nor do I have/use any CC

2. The lot traits are Homey, Good Acoustics, and I think Natural Light or something like that

3. I do not want to set the lot to a private dwelling

4. I have my locks set to "locked for everyone but household"

5. The sim who entered the house is a randomly generated "townie" sim who is not known to any of my other sims

6. The sim who lives in the house lives alone

7. The sim who entered the house does not live in/on any of the houses on any of the lots

@Purrpledrank Please run a game repair [ Open Origin, click 'Game Library' then right-click Sims 4 > Repair Game ]. Make sure to let it run until it has completed all repairs (it will do the base-game first, then run through each of your expansions/packs)

Please see if you can get the Sim to join your household. You may need to bring the relationship up higher to get that option. Then you will be able to control them - or delete them.

What is the name of the townie? Are they still on the lot if you close the game without saving? Maybe they will be gone, and had just glitched out.

This has now happened to me in all of my houses lately! At its worst I've had up to 3 sims at the same time that pretty much moved into my house and make themselves right at home. They make meals in the kitchen and leave messes, sleep in beds, and take showers and there is no way to get them to leave!! The only way I have been able to is to travel somewhere and as soon as I get back I lock all of my doors except for my one Sim that lives there but then it's super annoying because I can't invite anyone over because they can't come in the house! And as soon as I unlock the doors at least one of them shows back up quickly and moves back in, usually the same sims. And same issue, no way to get them to leave, no matter how mean you are to them. Wish they would fix this issue, it has gotten quite bad in my game now. 

@timewaster001 You could make a bug report for it and see how many other people will add details and 'me too' the report to see how common the issue is. If you do please mention it here so we could see if this thread can be merged into it.

i still have this problem

@runotytto @Purrpledrank @timewaster001 I have just made a more thorough list of thing that you can check for with this issue if any of you want to look through to see if anything is something you missed.

I was just chatting with @EuphorialQueen and she mentioned that if the sim is in Sulani that can be the issue. The way they look at neighborly social interaction and welcome into the lot/home os more open and works a bit differently by default there.

(NOTE: There is a current bug that may affect this trespassing function. You may, for now, need to reset the trespassing choices each time the lot is left or you exit. Learn more about this: Door Function Resets Upon Travelling or Exit ). – Thanks, @EuphorialQueen 

I've had one or two before but I just had 5 sims a mix of known and unknown shown up without wanting to leave.

The game is acting like they are just active in the neighborhood, not inside my house.

I just moved a bed in my living room and had my sims woohoo which made everyone leave very suddenly. 😅

It's definitely a weird bug though, it was kind of irritating at first though.