I am going to tell you the address of a great place to shop for vintage home decor in Paris (at least I think so). I am a bit torn as I sort of want to keep the store a secret. But the last time I was in the store, I spoke with the owner for a bit. He speaks English and is quite friendly (although he wouldn't let me take photos inside).
I mentioned that there doesn't seem to be many stores left like his in Paris. He agreed and said that his store had been in business since 1971. I want him to stay in business for another forty years, so I am going to give you the address.
Just off of rue de Passy in the 16th arrondissement is Passy-Brocante, 5 Impasse des Carrières, 75016. The fairly large store is filled with antiques and bric-a-brac in a variety of shapes and sizes all with pretty decent price tags. Although the lightening is a bit dark and the pieces are somewhat haphazardly displayed, you would be hard pressed to not leave the store without a treasure or two. It was silly of me to think of keeping this place a secret. I really hope you get a chance to visit Passy-Brocante (no website). Just don't buy all the cheese plates, I am starting a collection of them.