This is exactly the same situation as the motor circuit
that "we" ( I ) did yesterday.
Wire it up exactly the same as that one, with the light bulb
in place of the DC motor.
See the attached drawing.
Your finger goes in place of the switch and resistor.
When you touch the contact points, a tiny bit of current
from the battery flows through the resistance of your
finger and into the base. The transistor amplifies this
base current into a large collector-emitter current that
lights the light.
