When opposite charges move separately, THAT is when interesting things occur. If the negative charge in an object should start moving while the object's positive charge stays at rest, then we call that motion an electric current. With magnetism, the lines of force spring from the north and south poles of magnets, and these lines seem to connect the opposite magnetic poles together. Charge is not invisible. When light bounces off of an object, it is bouncing off of those electrons which form the outside of the object's atoms.
Electric charge reflects light.
The balloon is made of charge, and the amount of charge that is added or removed by the hair is incredibly small. But the poor balloon would instantly explode violently outwards because alike charges on its surface would fiercely repel each other. It's these same electrons which flow during an electric current. Even though the charge is visible, its flow is not. Look carefully at wires in an operating electric circuit and you won't see anything moving along.