Sudsy4,
We do a lot of stores in malls where night lights are common.
I'm not sure if there are any "requirements" but it seems that as long as there are enough lights on to see if anyone is in the building like an intruder or as long as you could walk through the building with only the night lights on it should be OK.
Also, the emergency lights and exit signs are usually connected to the night light circuit.
If you need further assistance, you might want to check with the department of Labor & Industry.
