I recently came across a problem. The contents of the launchpad, somehow, got corrupt. I was seeing files that shouldn’t be there. So… how did i fix it?
Open this folder:
~/Library/Application Support/Dock
(CMD + Shift + G… and paste that!). Once you’re right there… you’ll need to delete delete the “.db” file. Last step… relaunch the dock!
killall Dock
That’s it!