At the end of the school year there are often many items left in the lost and found. Contact your locals schools and ask them what they do with these items. Mention you are having a fundraising yard sale and see if they will donate the items. Most of the time they end up just throwing out anything left behind.
For larger items, consider searching the streets around campus on moving day. Many college students throw out their furniture and household items rather than move it. Many of these items are in great condition and could bring in some good money for your fundraiser.
