Package files for the Sims 4 are showing up as sims3.package files?

Hello.
Sims 3 package files won't work in your game. Check to see what the name of the files are and if you recognise any of the names from sims 3 CC that you have downloaded.
Do the files have the same name as they did when you first downloaded your sims 4 cc?
Have you downloaded any new CC lately, that you may have thought was for sims 4 but was for sims 3.
It would be best to take them out of your mods folder.