Apartment's Hallway Lights Controlled By My Unit's Circuit Breaker
Yes, a lamp is on one circuit.  A circuit is powered by one circuit breaker (hopefully!!)  In North American practice (and most others), a circuit breaker sits in a service panel.   Any service panel is fed by only one electric meter, because of billing and safety/Code*. 

Modern building and landlord codes require either a) a separate meter for the Commons Areas separate from any tenant meters, b) everything on one meter and the landlord pays the electricity, or c) the landlord uses sub-metering to divide the complex as in a).  However, these are fairly recent Code changes, and old buildings are grandfathered (do not need to be upgraded simply because Code changes). 

However, this may not mean you're paying for the hall light.  Lights which are on at certain specific times use a known amount of power.  For instance, look at any town's street lights.  They do not have meters. Nor does the city have its own power distribution system; they are simply clipped onto the utility's 120/240V/277V/480V distribution.  How are they billed, then?  Easy: it's known how much energy the light fixture draws, and most parts of the world, night averages 12 hours a day. 

So in similar vein, you could compute the lights' draw and ask the landlord for a rent concession for that amount; however most likely, he'll tell you that's already been done and is already factored into the rent.  So, there you are. 







* If someone really, really, really wanted to power a panel from 2 meters, one could use a generator-style interlock to isolate them but allow the meter to power from one or the other.  It would be sheer madness to wire it to draw from 2 meters at once.