There are 2 possibilities that can cause what you described.
1. If you are using a wireless mouse your batteries could be getting weak or your receiver could be miss aligned either one of these can cause a false click. The mouse loses its signal and the game read that signal loss as a click.Cure. replace batteries and or move receiver.
2. If you are using a wired mouse your cable whether it be a ps2 mouse or a USB mouse the cable could become unplugged slightly and causing a signal loss again the game reading the signal loss as a click.Cure . Make sure your cable is securely plugged in.
3. This pertains to both wirelessand wired mice. As you mouse ages the contacts wear and worn contact can cause false clicks if they loose contact with the button, This is especially true of the mice that come with most PC. They are very poorly made and their contacts wear out very quickly. cure.Replace mouse. If possible replace it with a good gaming mouse.