What could you do to a closed circuit consisting of 2 batteries and 2 light bulbs and a switch too increase the current?

The switch will not increase the current. The only thing that will increase the current is adding a larger load.

Another Answer

To maximize current flow in a circuit with 2 Flashlightbatteries, 2 Flashlight bulbs, and a switch, set aside the bulbs, put the batteries in series, connect the switch between the end poles of the battery set, and close the switch. The batteries will get hot and probably leak electrolyte, and be drained in seconds.

If you want to maximize current through the circuit withthe bulbs in it, connect the bulbs in parallel to each other, and in series with the switch.