Help! refrigerator has an odd whistling sound after I clean it?

I defrost my personal fridge today, after I remove a chunk of ice on the tray I heard a whistling noise coming from somewhere, I check if there's a cable under neat but there's none, and i found out that its coming from a corner. I check it and smell something like solvent.. Im not really sure if the sound is there before bec its the first time I actually defrost it. my question is, is there some dangerous chemical that can emanate and harm my food I store there??