My Mac keeps typing and scrolling uncontrollably

For the past two days or so, my Mac desktop has periodically kept scrolling down to the bottom of the page, and typing space bars into the search bar. If you scroll back up or delete the spaces, it will just scroll right back down and type more spaces in. The only way to fix this problem is to shut the computer down.

I installed Mac OS Sierra 10.12.1 on Wednesday, Oct. 26 and this may be the cause, as it first happened on Thursday morning. Since then it has happened 3 times in the last 3 hours.