How will it work? If you take a look at the datasheet of the 555 Timer IC you will be able to see #2 pin is the trigger of the IC. In this circuit it is triggered by the induced voltage of human body, the output will go high for a time determined by the 5Mohm variable Resistor & 100uF capacitor. Although it will get low after a few moments and the IC will stop providing output meaning the load will be turned off as well. A small implementation can be made to stop this from happening. The load can be anything, it can be small audio circuit, some LED lamps or a relay to drive more stuff! You can also do a lot of experiment with this circuit!