Are you a Comcast customer? Your home is about to become a public hotspot.

Some time in the next month or two, the company will be flipping a switch in Sacramento and San Francisco that will have thousands of private routers provide public Wi-Fi. 

"So when the babysitter is over or the relatives come over to visit, they don't have to ask for your Wi-Fi password," Bryan Byrd with Comcast California said. 

Byrd says the move will fill in gaps in free coverage already provided from apartment complexes or businesses.

He says the signals from routers will be divided and there's no threat to customer security.

And customers can opt out of taking part, Byrd said. 

Users who sign in once to the broader networks will never have to log in again.

They're already up and running in Houston and Seattle.