Q: touchpad on macbook pro stopped working, but magic mouse works fine

sudden onset... Any software additions/upgrades/updates?

see this article > Trackpad or Magic Trackpad is jumpy or erratic - Apple Support and attend to the "rule out non-Apple software" near the bottom - the rest is interesting as well.

I have a really big problem with the "proximity" of my fumble fingers (two instances in this short post!!)

If you can rule out the software and other issues, likely a hardware issue that may require a hands on technician - things get old and wear out

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Hello marie.jess019 and welcome to Apple Support Communities,

Need to know the exact model, size, year built, RAM installed and OS you're running.

I'd possibly suspect the battery - have you checked its' status lately?