When I was an undergraduate Physics major we would cook hot dogs by plugging them directly into a 120V outlet. This was a relatively hazardous operation as we simply attached the ends of an extension cord to two bolts, which were inserted into the hot dog. If you weren't careful and touched these bolts ("electrodes") while the cord was plugged in, I'm sure you can guess what would happen. Recently, after experimenting with a similar setup, I decided to build an electric hot dog cooker that would be much safer.
I wanted the key feature of this hot dog cooker to be an enclosed hot dog tray with a switch to ensure that current could only flow to the electrodes when the cover was closed. I also wanted to add a dimmer switch so that the current flowing through the hot dog could be varied. Previous experiments seemed to suggest that the hot dog was charing in the vicinity of the electrodes before the dog was fully cooked. As soon as the hot dog chars around the electrodes, conductivity between the hot dog and the electrodes decreases to the point where cooking cannot continue. By being able to decrease the current flowing through the hot dog, I hypothesized that cooking could be slowed and localized charing avoided. The final feature I wanted to add was a light that could indicate the level of current flowing through the hot dog.