I have a very old television that was given to me a few years ago, from its appearance it's probably from the 1970s, but has worked fine. I unplug it every night (along with the converter box), and a few nights ago started noticing it has a heat smell inside the back when I unplug it. The last time, though, it started sizzling inside the back when I unplugged it. Haven't plugged it in or used it since- is it possible it could catch fire if I use it again?