How do you turn it off?

I do not want "public wifi" in any way shape or form on my equipment.

It is a security risk as well as a liability risk, not to mention free advertising for Comcast, which I do not wish to be providing or paying for.

How do I disable it completely?

Am I forced to put the modem in bridge mode inside a metal cage and use a separate unit to provide private wifi for my business as others have done?

Thanks