Here is my setup based on an IT friend's suggestion. Modem and wireless router are in the great room. one network wire connecting the wireless router is plugged into the cat-5 outlet back to the box , so only the switch is in the closet. The cable modem should connected to an Internet router first. If you need more wired network port, then use one of the router network ports, and cascade to a network switch.
[Internet] -- [Cable modem]--[Wireless Internet router] -- [Network switch] -- [Wired PC]
)))))) (((((( [Wireless laptop] |-- [Smart TV]
)))))) (((((( [Smart phone] |-- [Media player]
)))))) (((((( [Tablet]