Verified answer

Do you tend to press the buttons really hard when you're playing? If so, that could be the problem. Also make sure that you keep your guitar in a place where it won't get stepped on or anything dropped on it. If you have been gentle with the guitar then maybe someone else has pressed the buttons too hard.

Where did you buy your guitar? If you bought it at Toys R Us and have a Buyer Protection Plan on it, you can take it back to the store and get another one. I hope this helps!

It's because the wire is probably disconnecting or the flow of electricity is being stopped by something. I'm afraid you can't fix it. Happened to me. I had to get a new guitar.