An intercom system can be hugely useful in moderate to large sized homes or businesses. They work as a fast, efficient means of communication between one another. You can also include a paging system, and play the radio or music of your choice throughout the premise. Along with the obvious utility of speaking to whoever is outside of your property requesting to come in.
Installing a home intercom system requires some carpentry knowledge, as well as being familiar with the electrical wiring. Note that there are some intercom systems that use battery-powered, wireless modules to power the system without running wires in the walls.