I would first run a Malware check on your PC. Also use your Anti-Virus to do a System scan for malware.
Mice normally doesn't move by itself nor click by itself unless someone has control of your computer.
Otherwise without any information about your computer setup that is all I will suggest until you post your Computer hardware.
EDIT: If you are using WiFi to connect to the internet it is possible someone has tapped into your WiFi network thus being able to control your computer.
If you disconnect the WiFi and the same problem continues then it might be a malware infection.
Doing a fresh install of Windows will remove most malware unless the malware has infected your BIOS so you will need to do a Boot scan or Boot-Time scan.
This will check the computer before Windows boots up for viruses or malware.
