Dick Van Dyke Show Theremin

I just watched an episode of The Dick Van Dyke Show which featured a Theremin. It is in season 2, episode 20 "It May Look Like a Walnut!". Funny episode with well done Theremin use, right from the beginning! Check it out!

In the score, or does a theremin physically/visually appear in the episode?

I know this episode, it;s about Dick Van Dyke encountering a UFO and Danny Thomas as an alien with eyes in the back of his head.
The theremin is used as usual, the digetic voice of the UFO (digetic, I've loved that term ever since i first heard mentioned about the theremin and use it whenever possible)
Anyway i haven't seen it in a long while, but with tannermin being used so often on TV in the 60's, it could be that.

Andy

So it's only heard and not seen, then?

from what i remember, it's only heard. Of course i could be wrong. It's been a while and I last saw it before I really got into the theremin.
Now that I think about it, there might have been two featuring a UFO. The one mentioned has Danny Thomas as an alien and it sort of became an Invaders from Mars/Invasion of the body Snatchers type story with walnuts. It turns out to be a dream.
Another one is Rob ( Van Dykes charactor) working late and seeing a UFO ( it makes a noise that he says sounds like "Sony Tuffs")
That one turns out to be a tou maker in the building trying out a new toy.
both have a sci-fi theme, and both could of used some form of theremin in them.
Back to the origional question (wheeew) i don;t believe you see a theremin in any of these episodes
Andy

Correct, a Theremin is not actually seen, just heard. It's fun, though, since both characters specifically comment on "that scary music", referring to the Theremin. 'Rob' even whistles the special effect of the space ship (mimicking the Theremin).