Name That Trauma:: Mike B. on a Supernatural Neighbor

I remember something from when I was a kid that I wish I could identify. I seem to vaguely (and perhaps incorrectly) recall seeing something on TV where a couple lived next door to an eccentric/reclusive rich guy, who they may or may not know/suspect to be not-quite-human and/or in possession of some kind of supernatural abilities. Anyway, the man in this scheming couple sends the woman over to seduce or at least get close to the rich guy so she can get access to his safe or other riches when he's not around. I don't recall how long this plot gets drawn out (maybe the rich guy grows to think she really cares for him over time or maybe he quickly catches her trying to slip away at a dinner party or something), but at some point he walks in on her trying to get his stuff, realizes what's been going on, and (possibly as an involuntary reaction or perhaps deliberately) "does his thing", which I think might have been depicted with him emitting a high-pitched shrieking/whistling noise or something. Maybe she screams, but I don't think we see the effect of this incident before it cuts away, back to the scheming man, who hears the woman come home and enter but doesn't yet see her when he asks how things went or whatever. She then is seen approaching the man as she starts to say something like "It's alright…" before the man turns around in horror as he (and the audience) sees that her face is disfigured and she says something like "You still love me!"

I recently saw a clip from the 1978 movie "The Medusa Touch" that kind of reminded me of the (distantly remembered) intensity of this scene, with some of the same elements, and that film's main character's telekinetic powers could almost fit the bill (and I even think his last name of Morlar seems to ring a bell), but the scene and overall plot don't otherwise match my memory, so perhaps I'm conflating two different films…

Now the funny thing is, I had seen a really short clip (HERE) of a much lower-budget movie (maybe even the scene I'm remembering) years later in part of the video intro at a Weird Al concert (which he apparently first used in a 1987 concert, so the film must be from 1987 or earlier if that's true).  Luckily, I found this video online some time ago, and now I found your website.  If this is the movie, the clip is a bit different than I recall, as it appears the scheming man has been captured by the rich man and strapped down to a table for some other horrors when the woman enters and says, "Don't be afraid, Jason", but maybe I'm just misremembering it or this is a later part of the movie. Any ideas?  Thanks.