Don't laugh but there is actually a website that shows you how to make your own homemade morse code keyhttp://www.chss.montclair.edu/~pererat/m9900.htm
This project is designed to introduce children to the principles of the electric telegraph.
It uses readily available parts:(12KB)
2 Pieces of wood.
8 small screws.
2 large nails.
4 flat strips of metal. (One MUST be iron-bearing or "ferrous" metal).
20 feet of INSULATED wire from 18-28 guage (around 1/32 inch diameter).
2 flashlight batteries.
The Key:(14KB) consists of a strip of metal which can be pressed down to make contact with a screw.
The battery holder:(14KB) holds the flashlight batteries and makes electrical connection with each battery.
The Sounder:(12KB) consists of about 100 turns of wire wrapped around a nail which attracts the iron-bearing strip of metal and makes a clicking sound. When the sounder is deactivated, the metal springs upward, striking another nail and making a second clicking sound. Dots and dashes can be distinguished from each other by learning to tell the difference between the pull-in click, and the release-click.
Now THAT'S What I Call Ham radio!!