Are you using the computer's trackpad or an external mouse?
Go to System Settings > Accessibility and see if any options are turned on, particularly in the "Motor" section.
If you are using the trackpad and not an external mouse, there could be a serious underlying problem. See this checklist::
Check your battery for swelling. Symptoms:
— Unexpected trackpad and/or keyboard behavior including random input.
— The gap between the display and the deck is not even when the display is closed.
— The gap between the bottom plate and chassis is uneven in places.
— Some of the screws that secure the bottom plate have popped out.
— The trackpad surface is higher than the surrounding deck surface.
— The computer "rocks" a bit on a known flat surface†.
† I find solid-surface and granite countertops very effective flat test surfaces.
A swelling battery can enlarge at an alarming rate as if fills with flammable gases. The is enough force to render the computer non-repairable in days. If you find this is the issue, do not wait to get it addressed.