You mean, one-way mirror as in horror movies? :) Sorry, couldn't resist...
Yes, they do make mirrors like that and they also make films, usually called "privacy" or "one-way" window film (like these: ) and in your case you need to pick films that would withstand the humid environment of a bathroom.
If you can elaborate on the actual application (although I'm almost certain it's for the window), I can look something up specifically rated for the bathroom environment.
- posted 7 years ago