Shouldn't this be मेरा घर instead of मेरे घर ?
No, there is an implicit preposition ko (to my house) that is omitted for brevity, but it still turns the house into oblique case: "mera ghar" becomes "mere ghar ko".
Hindu he kya?
Is it मेरे घर and not मेरा घर because of the past tense?
No, only because of the "ghostpostposition".
Hrishikesh which school?
What's wrong with पीटर ने मेरे घर आया?