How do I prevent my Mac from switching Wifi connections when at home? I have a MacBook Pro, running Mac 10.9.5.  I connect wirelessly to the Internet through my home Cisco LinkSys E900 router, which sits just 10 feet away from my computer.  However, frequently when I leave my computer inactive for a period of time and then return after waking it from hibernation, my Internet is connect to an xfiniti Wifi hotspot, without my having done anything.  How do I configure my Mac so that it will ignore the xfiniti Wifi hot spot and remain connected to my home network?
Looks like the computer is set to prefer or prioritise the xfiniti Wifi hotspot over you home wifi, you can set your home Wifi to be of priority to any other Wifi connection and this is how to do that, 

System Preferences/Network/ then select Wifi and click on Advanced, you'll see all preferred networks there. 

Click and drag your home Wifi to the top.