Whenever I'm on a service call for ingress, the first thing I do is shake the wires behind the TV and see if it comes and goes. Half of the time that is the problem.
Push on connecters are NOT your friend and are a very common cause of ingress. Screw on ones are very annoying, but they are much more secure.
If that is not your problem, then it's probably the wiring. If you have a long cable running around the room from the cable outlet, take a look at it and make sure it says RG6 on it. If not, I strongly suggest you pick it up, throw it away, and head out to Wal-Mart and buy a decent quality cable.
If you've done this, and you still are experiencing ingress, then it's time to get some wires replaced. If you aren't scared of running new lines, go to your nearest hardware store (I recommend GrayBar) and buy a thousand feet of RG6 and start running new lines.
If you don't like doing work like this, see if your cable company offers any kind of wiring maintenance plan. They are usually pretty cheap ($2 or $3/mth) and will get you new lines run for free.
I recently went to a house to rewire it because they were having tons of problems. I located their junction and found this horrible piece of work:
Welcome to ingress hell.
Note by wth : You also need to pull the wallplate off and check the cable & connector on the backside of the plate also.
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