Would it help in this case? Sure, you'd prevent signals from leaving the house, but the signals in this case are all internal to the house, so the wifi would st

Would it help in this case? Sure, you'd prevent signals from leaving the house, but the signals in this case are all internal to the house, so the wifi would still work internally. All you'd prevent are outside services from pinging in and vice-versa, not much help for internal devices connected through broadband internet wired or fiber.