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@klperkins67  Uninstalling the game itself doesn't remove the Sims 3 user folder, the one in Documents > Electronic Arts.  This is where user-installed content, for example anything you download from the Store or Exchange, is stored, as well as saves and creations you save yourself in-game.

You can try this method of removing bad custom content:

https://sims3.crinrict.com/en/2011/01/tutorial-how-to-get-rid-of-unwanted-custom-content.html

Keep in mind that this sim will have also left a file in Library or SavedSims, depending on whether it's a household or a saved sim template (the type you access within CAS).  You can tell which file the sim corresponds to by checking the timestamps: this sim will have created exactly one file at the time of installation.  And it's also a good idea to remove the Sims3Pack in Downloads, which you can again find by timestamp.

If the above method doesn't help, make sure you've removed the corresponding file in Library or SavedSims.  Go into DCBackup and delete every file inside except for ccmerged.package, which is necessary to make premium store content work; everything else is extraneous.  Finally, go into DCCache and remove the highest-numbered file that ends in .dbc.  They're numbered starting with zero, i.e. dcdb0, dcdb1, etc.  (The files that end in .ebc are store content and can be ignored for this purpose.)  This will uninstall the most recently installed custom content, so you may need to reinstall a few other items when you're done.