I discovered how to wiggle my ears by accident as a child, probably about 8 or 10 years old. One evening, for no particular reason, I wondered how long I could hold my eyebrows up. I held them up for, I think, 4 or 5 minutes, and then, as it started getting uncomfortable, let them down. And as the strained muscles that had been holding up my eyebrows relaxed, I felt some other muscles, connected to my ears, also relaxing. And once I could feel them relaxing, I found that I could contract and relax them voluntarily -- i.e., wiggle my ears.
I'd be interested to hear whether other people, who aren't now able to wiggle their ears, but try the above trick, do or don't succeed!
Looking on Wikipedia, I see that we in fact have three sets of muscles that can move our earlobes. I guess I only learned in my childhood to use the "superior auricular muscles", which move the ears upwards. After reading this, I tried modifying what I describe above by holding my eyebrows forcefully downward for a while, as though frowning; and when I released them, I did seem to feel a slightly different muscle-relaxation; and when I contracted and relaxed those muscles, it felt as though they were moving my ears forward a bit and letting them back. Contrasting the upward and forward movements, I was able to come up with what feels like a third pair of muscles, which move my ears backwards. But looking in the mirror, everything I do just seems to move my ears up and down.
However, at night, with one side of my head on the pillow, I find that if I try moving my ears in these different ways, I do feel my head pushed in different directions.
Something else I've been able to do for most of my life, though I've hardly ever talked about it because, unlike ear-wiggling, it isn't something that other people can see, or that I could tell people how I learned to do, is to somehow create a brief rumbling sound in my ears (which tends to make me a bit sleepy for a moment). A few days ago, however, I realized that aside from deciding to do it, there are other actions I can do that can briefly produce it: "swallowing air", making myself burp, or yawning.
So I wonder: if people who have not been aware of this phenomenon try yawning, or swallowing air, and pay attention to the sensation in their ears as they do it, will they also notice a momentary rumbling sound and sensation. And if so, will they then be able to bring it about voluntarily?
Looking online, I see that https://en.wikipedia.org/wiki/Yawn says (in the third paragraph), "The tensor tympani muscle in the middle ear contracts, which creates a rumbling noise perceived as coming from within the head ...", with a link to a page "tensor tympani muscle", which has a heading Voluntary control, where it says that "According to the National Institute of Health, `voluntary control of the tensor tympani muscle is an extremely rare event'". But perhaps, if one tries what I suggest above, it will be easy to learn how to do. Again, I'd be interested to hear, from people who try, what the outcome is.