I’ve got Mac OSX 10.10.3. Recently the “p” key seems to be pressed. It is “pressed” about every 1 second or sometimes a couple times per second. If I use the shift key it stays lowercase but if I type letters on my keyboard including p the typed keys are uppercase. If I use caps lock on the keyboard it also still stays lowercase unless I type keys on the keyboard including p.
Anyway if I disconnect all of the USB cables it still happens. I’ve tried restarting the computer and it kept on typing in the password field. But luckily my password is 3 characters so I was eventually able to type it in without the p being in there.
I’m trying to use the system preferences menu but I can’t access the items because it is typing p’s into the search field in the upper right.