Audio Systems: TV connected to surround sound, stereo system, speaker system

Question
Hello,
I have a speaker system built into the walls of my home,  and it is currently connected-- wired directly-- to an older stereo system.  If possible, I would like to set it up so that I can switch between it and my television, or, if not, then connect it directly to the TV. The wires from the speakers come directly from the wall, so I guess I need to strip and connect wires, yes?  How is this done?  Thanks so much!!

Answer
Before I can answer anything - I need to know the brands and models of the TV and the stereo system. The main reason is that different brands have different configurations, and I want to be able to tell you exactly what is possible with your particular gear.