Occasional odd behavior when waking MacBook

[CaliforniaMini]

My MacBook works fine most of the time. Occasionally when I wake it from sleep and enter my password and hit enter, the password string will continue, as if a key is stuck, or someone is entering it remotely. It seems to happen in a group of about five keystrokes and then a pause and then another five and a pause, etc. Finally that stops and it tells me the password entered is incorrect. But it won't respond to the keyboard. The only way out of this I've found is to force shutdown, or close it, let it sleep and then open it again. It then lets me enter the password and it unlocks. But after this, I start having more various problems and am forced to restart. For example the mouse, keyboard, or both may become unresponsive, apps may lock up, become unresponsive or quit. After a restart, all is fine. This doesn't happen very often, possibly once a month or less. And the only time it happens is waking from sleep and then progresses from there. Anyone experiencing a similar problem? I can't find anything on Apples site. This is the only Mac I lock on sleep and the only one I have this problem with, so I don't know if its related to being password protected or not.

Thanks!!!
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