My TV is squeaking

My TV started making a squeaking noise after we had a power outage. Before the power outage, the TV was working normally and had never made this noise. After the outage, it started squeaking while plugged in. I unplugged it completely overnight, but when I plugged it back in the next day, the squeaking started again. My boyfriend lightly tapped the outside of the TV near the power button, and the squeaking became faster and a little louder. It continued making the noise until he unplugged the TV. What could be causing this, and is it safe to use the TV?