Movie or series in which people are shrunk and go inside a man's head, manipulating him

Question

I saw this movie in excerpts on TV (it may be a series) around 1992 +/- 5 years or so?

I only remember that some people (I think it was more than one person), possibly teenagers, were shrunk and somehow got inside a specific man, who didn't know about this. There were scenes where, from inside the head, they could then see through the man's eyes into the outside world.

There were kind of receptors in the head that the people could hit, which resulted in the man taking a specific action. They started to test them out and wrote notes on these receptors. The goal was to make the man do something at some point.

It's not any of the following:

• The Fantastic Voyage (1966)
• Innerspace (1987)
• Herman’s Head (1991)
• Being John Malkovich (1999)

Answer 1

You have probably seen the Krecek v nocní kosili (literally the "Hamster in a Nightgown") the Czechoslovakian TV Mini Series from 1988–1989.

From the IMDB:

Who knows how it happened that Kája Berka forgot to take his pajamas with him to visit his grandfather and grandmother in Rosebach. His great-grandmother willingly lent him her great-grandfather's nightgown, who was said to have been a ridiculous dreamer and inventor of nonsensical objects. Only my great-grandmother considered her late husband, a professor at the local high school, to be an unacknowledged genius. Kája, after sleeping through the night in his great-grandfather's nightgown, gave his grandmother the full benefit of the doubt. Not only did he experience a trip to prehistoric times in his great-grandfather's class, but he learned an important piece of information here. His older brother Radim, a designer for a large automobile company, had long been struggling with a groundbreaking invention. His great-grandfather tells Kája that he himself once worked on a similar invention, a car that would run for free and without harmful emissions, and buried the important documentation in the garden.

After the invention is stolen by main antagonist Mr. Hamster, Kaja with friends use another great-grandfather's invention to shrink themselves and climb inside Mr. Hamster's head, to control him by bumping the neurons of his brain and make him to confess and return the invention.

YouTube clip from the series, where the kids control Mr. Hamster.