Mice have caps in them too, but I've yet to have a mouse go bad on me, so I've never taken the time to swap out the caps. And that holds true for mice manufactured in 1984 and earlier.

Here's a Mac 128k mouse PCB photo that reveals two electrolytic caps inside. Technically speaking, it would be good to replace these with tantalum caps in order to restore the mouse to the same electrical functionality it had shortly after manufacture.