Putting Finger in Ear and Feeling Vibrating / Clicking As If Nerves / Muscles Were Misfiring

Misfiring? Not sure what you mean. Clicking sounds could be coming from the middle ear bones. Normally if you put fingers in your ears and you hear a rumbling sound, that's the muscle fibers of your arms that are twitching. Muscles are never fully at rest, they can twitch. It could be this that you hear.

It's also possible that it could be tensor tympani muscle that's vibrating. Try to sit comfortably and relax your jaw and see if it stops. I have a problem with the tensor tympani and relaxing my jaw usually helps to some degree.