Well if it’s your mouse, then obviously yes, it’s possessed.
Funny, just a couple of days ago, I bought a new mouse because my Logitech optical wireless mouse had been doing exactly this. Eventually, it just got too annoying.
If it’s a plunger type switch in the mouse button you may have dimpled it by pressing hard. This is a common problem with push-to-talk micro switches in airplanes. The more you mash it the more dimpled the contact and the worse it works. You could actually make multiple contacts because of the uneven surface created and thus trigger multiple input signals to the computer. I solved this by going to a different type of switch in the airplane but that won’t help you in this case.