I am a brocante fanatic. Here's my favorite website:
www.vide-greniers.org
Scroll down about a half a page and you will see the various cantons in Switzerland. Click on Vaud. Or, you can click on the map on the right where it says "recherche sur la carte" and search that way.
Vide grenier means attic sale and the quality of stuff is equivalent to a yard sale or garage sale.
Brocante is a step above and will include some antiques and furniture.