Uninvited sims appearing on vacation lots

Thanks PipMenace! I'll click on my sim next time I send her on a vacation to see if this option appears.

If you do get the option CGrant56 mentioned, it looks like this:

...but I've found it to be somewhat unreliable even on my home lot. If the game has bugged and doesn't register the extra sims as visitors, then the option won't be available.

I'll try to click on my sim the next time I send her on vacation and see what options are there.

So far, I've only had my sim vacation in Granite Falls because I've had her collecting bugs. 
I'll have to try to send her on vacation in other worlds and see if there are sims on the vacation rental lot there, too, who don't leave.

I only have 3 clothes mods, so hopefully they don't interfere with how the vacation worlds work.

When the vacation rental lot in Granite Falls loads, there are always a few sims standing there. The park ranger visits briefly after my sim arrives.
When I had my sim rent the largest cabin, there appeared 5 adults/young adults, 3 toddlers and 3 pets! And they wouldn't leave!
I usually have my sim rent the medium sized cabin. On that lot there are usually 2 extra sims when the screen loads.
My sim had the Scientist career, and she invented a freeze ray. I've used that on the unwelcome sims and so get them out of the picture for a few hours. LOL!

Thank you so much for taking the time to answer me!

ebstokstad​  The option should be on your sim.  However, if the sims are already leaving, the option probably won't be there.  It allows you to send home all unwanted visitors.  Sometimes it will be there, sometimes not though.  If you play with mods, MCCC has an option to send specific sims home too.  However, I forget if it will work on sims you can't click on or not.  

But backtracking a bit, you're on vacay in Granite Falls.  When I vacation there, every time I travel there, there are always 2 sims standing in front of the rental where I'm staying.  They are OR role sims usually.  Most often one will be the park ranger or a bear.  And GF always has a lot of walk by sims strolling around which are there when I arrive at the rental.  But when I get the extra sims on arrival, they always leave.  Most of the time they walk away and other times they just disappear.  It seems that many, if not all of the sims in GF are really hard to click on too.   

So, it sounds like you have the same thing going on except the extra sims don't leave.  To me, that means there is a difference between games.  It's not a bug or else it would happen for me, and others would be reporting it too.  So, a couple questions:  

Does it happen in Selvadorada too? Or any of the other worlds where you have vacation rental lots?
Do you play with any mods, and more specifically any mods that changes how the vacation worlds work?

Hope this helps

If I click on the uninvited sims, there is no Send Home option on them, like it is with sims that come to visit my sim's home lot.
Is there a Send Home option on my player sim that will send the uninvited sims home? I¨m afraid I don't understand.

ebstokstad​  No, the option I mentioned is not Go Home.  To go home from your vacation, the usual way is to use the End Vacation option on your sim's phone.  The option you are wanting to use is Send home.  I can't remember the exact wording, but it will not send your sim home when you use it.  If you do end up getting sent home, you've used the wrong option.

Hope this helps.

I've only sent my sims to Granite Falls, which came with the Outdoor Retreat game pack. 
The uninvited sims show up at all 3 cabins (lots).
If I try the send home (or similar) option on my sim, won't that send her home from vacation and end it?

ebstokstad​  What world is your vacation rental located in?  

In some worlds, when I load the rental lot in lime mode, a couple of extra sims will usually be there but then leave pretty quickly.  So, it is not uncommon that the sims show up.  What is odd in your case is they stay around.  Since you get no options on the extra sims, have you tried the send home option on your sim?  That is not the exact wording of the option, but you should see something similar on your sim.

Hope this helps.