Where Are You?

I have compiled examples of the "Where are you?" routine.  But, first, it is necessary to provide context for a few of the scenes.  

In The Navigator (1924), a couple (Buster Keaton and Kathryn McGuire) are unaware they have become stranded alone together on a deserted ocean liner. 

In Mighty Like a Moose (1926), a husband and wife both have adultery on their mind.  In preparing for their illicit dates, the couple sneak around their house with great caution to avoid one another.  

The More the Merrier (1943) involves a housing shortage that brings together three unlikely roommates.  An initial arrangement is made by a government advisor, Charles J. Pendergast (Charles Coburn), to sublet half of  an apartment from Connie Milligan (Jean Arthur).   But then, without consulting Milligan, Pendergast sublets half of his space to Joe Carter (Joel McCrea), an army sergeant who needs a place to stay while he's waiting to be deployed.  When he first brings Carter home, Pendergast works desperately to hide Milligan and Carter from each other.

Then, we have Lover Come Back (1946).  William Seiter, the director of Sons of the Desert, guided George Brent and Lucille Ball through a scene in which the actors keep coming in and out of different doors while just barely missing each other.  The scene lasts twice as long as it should, but it has enough laughs to make it worthwhile nonetheless.  The premise (if it matters) is that a divorced couple is unaware they have both been booked into the same hotel room by mistake.   

Two blind men (Richard Pryor and Anthony Zerbe) engage in a gun duel in See No Evil, Hear No Evil (1989).

Finally, we have a scene from a 1957 episode of I Love Lucy.  The episode has a double-edged title - "Lucy Misses The Mertzes."  The Ricardos and Mertzes enter and exit the waiting room of a train station without seeing each other.

Film sources:

Five Golden Hours (1961) 
42nd Street (1933)
The Play House (1921)
The Navigator (1924)
Mighty Like a Moose (1926)
Be My King (1928)
Sons of the Desert (1933)
Rings on Her Fingers (1942) 
Lover Come Back (1946)  
I Love Lucy (1957)
Touch of Evil (1958)
See No Evil Hear No Evil (1989)
Uncle Buck (1989)

In Lonesome (1928), two lost lovers don't realize that they are hidden from each other by a sign.