For a more permanent pumpkin that can be reused, we can use a coconut shell. You will need:

• a saw
• a drilling machine
• a battery and an LED (can either be assembled manually or ripped out of a broken toy)
• a potentiometer or a switch
• a plastic LID to add to the bottom of the coconut

First cut the bottom (stable) part of the coconut using the saw. Then drill the holes for the eyes, nose and use the saw to cut the mouth - you can also use a flex machine which will take less effort.

After that, create the following circuitry and add it inside the coconut.

           +---------------------+
           |                     |
           |                     |
 Battery   |                    ---  /
         -----                  / \  /
          ---                  /___\    LED
           |                     |
           |                     |
           |         \           |
           +-------/\/\/\--------+
                       \
                 Potentiometer

The potentiometer can be replaced by a switch. In the pictures, the potentiometer is placed by drilling the head and is used to change the intensity of the light emitted by the LED.