Can I refer someone that lives in the same household?

Yes!  There is no hard limit on how many accounts are allowed per household, as long as each account is associated with a different person.

It's recommended to only use one account per household as our partners may set their own limits when completing offers from multiple accounts in the same household. For example, if User A and User B live in the same household, and User A completes a certain offer, it might not be available to User B.