I've grabbed tons of free stuff from
www.DriveThruRPG.com (and DMs Guild) and have incorporated what I liked best into my own homebrew campaign. If something is particularly good, I've even gone back and bought it again for >$0 to throw the creator a bone. Being that "non-commercial" means "not intended to make a profit" and a popular definition of "homebrew" is "anything created by players that is not an official product", I thought that DriveThruRPG might be helpful for you inasmuch as you can get a lot for free there. Apparently I missed your intent. Good luck finding what you're looking for.