While in a public-place, ever been mistaken by others as someone in authority in that particular place?

Haha yes.

I some how carry an "in-charge" aura about me.

Never.....................

not authority.. But At Talbots.... An older woman was shouting from afar about a price of something and I just glanced.. thinking.. how come no one is helping her... 

Then she approached me and started hollering at me, "Can you get me your manager? You are so rude." I told her, "OH! i'm sorry I don't work here."to which she replied, "What do you mean you don't work here?  I'm not in a mood to joke around."I just stared back at her.. and she was getting furious..  She went to the front desk to complain about me... and I was approached by the manager... and she replied, "oh she's not our employee.   What do you need help with?"I didn't get a sorry from the older woman.. just a simple smile from the manager... with, "Is there something I can help you with?"  

No but people ask me for help about finding things. Usually I don't mind helping since it's often someone older or someone new to a place 

No, never ............

Nope. There are too many boxes to check in this question.