Our apartment is a really cosy one with a huge shiny living room, a balcony, three comfortable bedrooms and a kitchen.
I live with two roomates (Jane and Rachel) and I propose to rent my room during the summer.
You'll stay in a quiet, nice neighborhood and will get easily around thanks to public transportation. Le Père Lachaise is 10 minutes away by walk, Place de la République is 10 minutes away by metro, Bastille is 15 minutes away by bus and Châtelet is 20 minutes away by metro.
Of course you will have to respect the rules of living in a community. Smoking is allowed on the flowery balcony only.