Here is a tiny Tesla Gun from the TV show Warehouse 13. It uses a burnt out christmas light bulb as the "vacuum tube". If you want, you can attach a small ring or cord, like I did, so you can use it as a keychain.

Step 1: Materials

Materials
-old Christmas light bulb
-scrap pieces of sheet metal; I used aluminum
-paint: black and silver (bronze or gold would be better, but I didn't have any)
-JB Weld
-paperclip (optional, only if you want to add a cord or keyring)
-cord or keyring (optional)
-Mod Podge (optional)

Tools
-metal cutters
-pliers
-wire cutters (optional)
-detail paintbrush (I used a toothpick, which worked fairly well)

Step 2: Cut Out the Metal Parts

Cut the pieces of sheet metal into shapes like these. They should look like the bottom part of the Tesla Gun, but one needs to have a rectangle on top about a half inch long and three quarters of an inch high. This part will be wrapped around the "vacuum tube" to form the cylindrical main body.

Step 3: Prepare the Light Bulb "Vacuum Tube"

Pull the bulb out of the housing so that you just have the glass bulb with wires sticking out. If you want to make it a keychain, bend a little loop out of paperclip wire, and tie the light bulb wires to it to keep it together for now.

Step 4: Assembly

Take the two metal pieces; there will be a part that is the same on both of them. JB Weld these parts together so that there are two identical layers. What you should have is a two-layer metal bottom part, with the rectangular part on the top. Take the light bulb, and apply JB weld to the part where the glass meets the paperclip loop. Using pliers, bend the metal rectangle into a cylinder around the light bulb. It should now look much like the Tesla Gun. Apply JB Weld to the outside of the handle and at the front where the end of the bulb meets the metal part. Wait for it to dry.

Step 5: Painting

Use a small detail brush or a toothpick for this part. Cover the handle area in black paint, and paint black rectangles on the sides of the metal part. Add details such as the dials and knobs using metallic paint. I used silver, but gold, copper, or brass would be better for the steampunk look. Allow to dry. If you want, you can coat it with Mod Podge to keep the paint from scratching off and to give it a shiny finish.

Step 6: Keychain

If you wish, you can make this into a keychain. If you have a small jump ring, you can attach a cord or keyring to the paperclip loop at the back. I made the ring from another piece of paperclip. Use a keyring to attach it to your keys, or use the cord, like I did, to attach it to an electronic device that has those two little holes for a cell phone charm or similar. Show it off to your friends.