Deleted Households Reappear in Library

@simsgamer3000  It sounds like OneDrive may have uploaded the files for these houses and is downloading the files again whenever you delete them.  So please check OneDrive's Documents folder for any Sims 4 data.

If you find a Tray folder there, you can delete the households manually, which will require figuring out which files correspond to those households, which in turn can be accomplished by deleting the households from within the game and comparing your main Tray folder with the one in OneDrive.  Or you can delete the Tray folder from OneDrive and upload your main one.  In that case, I'd suggest first making a backup of the Tray folder stored on your computer in case OneDrive decides to delete both folders at once.  Then you can just restore the backup with no harm done.