Is there a way to stop my old television from making this high pitched noise?

My television is about 6 or 7 years old now, one of those ancient things with the huge back on it (not a flat panel). So, recently it has been making this really high pitched sound almost every 15 minutes or so when it is on. Turning it off for a bit usually stops the noise, but within a few minutes it returns. It’s gotten really annoying. Is it possible to fix it? What causes this to happen? Anybody else experience this before?