Why is my MacBook typing letter "r" all by itself?

If you got a mouse connected remove it end restart and get a new mouse that mite be the problem

because that is the problem that i had once

Mine requires more pressure on the r key than the est.

i have the same exact problem with my ‘N’ key. it’s missing off the laptop keyboard, so i have to use an external keyboard, but it won’t stop doing this even still, so any answer will be gladly appreciated.

Cleaning the key does not solve the problem for me... unfortunately the ghost typing continues. At the same time, like Lancecharles, it's hard to get the letters to print when I want them (the i and u in my case). The ghost tho will type i's and u's (with accent) at random or stream them until I hit escape.

Like Lotusjohn, i'm using an external keyboard. I just plopped a bluetooth ontop of my mbp with a couple plastic rulers as separating platform between the boards.

Got the problem on macbook pro 13 early 2015. I know it's old but still working fine. For some reason the 5-% key totally stopped responding. I started to use virtual keyboard after trying to pop out the key and fix it without success. But now, not only does it work back but it keeps typing all the time in any app I am onto even at startup in the password window so it's even worst than before. If I do press it, it's typing several times whilst i only pressed once... also troublesome... try resetting SMC, no change... Appreciate any suggestion. Thanks