The Xfinity Home Security service will cost around $40 monthly, although customers will have to sign up for a three-year contract and agree to a steep $1,100 early cancellation fee.

Comcast is already seeing traction at its Xfinity Home security service, which launched in 2012. Subscribers have doubled to more than 1 million in the last two years, according to quarterly ...

Comcast Corp is adding home security to its package of services for homes where it already delivers cable television, broadband and phone.