What episode of the office does jim hint that pam should move in with him?

That comes from Chair Model in season four. Pam sets Michael up with her landlord and it doesn't go well. That's a really sweet scene when he tells her he thought he already proposed and she looks at her ringless finger. He tells her it's coming and she thinks it's a joke. But when he does his talking head he peeks to see if she's looking and pulls out the ring and says he bought it a week after they started going out <3 Then the fake proposals start :)