Tracing TV cable path in wall
Pick up a middle of the road tone generator and probe kit from a company you've heard of. No need to buy the most expensive model you can find, it will likely have features you'll never use. 

I've used this one Gardner Bender Wire-Tracker Wire Tracer, which I purchased from Home Depot for ~$40.00.  



It's not the best model on the market, but it worked very well for me. It was sensitive enough to accurately trace cables through both walls, ceilings and floors, and was able to attach to a variety of cables.  

This model allows you to connect the device to a variety of cables including RJ-11, RJ-45, and coaxial. It also has alligator clips, which allow you to connect it to electrical and other wires.

Make sure the power is off before connecting the tone generator. Some models can work on hot lines, but it's still safer to kill the power.