Sorry, I'm not sure where to put this exactly.

I use a laptop which sits on an inclined stand. There's a small (~5"x5") 12V fan behind it to help with ventilation, have been using it for more than a year now without a problem. I just noticed now that the fan's power adaptor makes a steady soft but very high-pitched sound. Not sure if it's been like that before and I just hadn't noticed, or its new state.

I've googled and results seem to be it can occur in adaptors, something about vibrating parts. Just wanted to know, sound aside, if it's still usable or can this explode/burst into flames or something?

Thanks!