Translation:He will call the wolf in my grandmother's house on Monday.
No, that would be (albeit oddly worded but the starting point isn't great:) "Han vil ringe ulven til min bedstemors hus på mandag". A better way would be "Han vil ringe til ulven på mandag og bede ham komme til min bedstemors hus" but that's a bit more complicated.
In this case the wolf is "i" - already "in" my grandmother's house. Poor grandmother.