isight light randomly turned on??

I have a macbook air, OS X Yosemite version 10.10.5.

Sometimes i notice that the little green isight light next to the camera will turn on randomly. Ive usually just ignoredit but today I was on safari and suddenly i noticed that the light was on. Photobooth was running but it wasnt open. Did it come on because photobooth was running? Im so paranoid that I covered the camera with a piece of paper.

I read that I should check activity monitor while the camera was running but i didnt see anything wrong.

Facetime was closed as well.

Maybe i clicked on the photobooth tab without realising it somehow? Im not sure what else to check for to make sure im not hacked or anything. Any help would be appreciated! Thank you.