For this assignment I began by testing conductive materials that would allow me to create an improbable switch. My first approach was a key that would trigger sound and light when inserted into a lock. After tests and fixes... It worked!!! :)
Later on I got curious about the possibility to created a device that could be placed in different locations, so it had the ability to be placed between objects, under, above, etc, allowing some flexibility in this respect.
I came up with a "pressure switch" that would turn itself off whenever pressure was released, and on otherwise. A flexible structure that would tend to go back to its original shape seemed to be a good solution, thus facilitating the closing and opening of the circuit when pressure was applied. A sponge was the best option I found to achieve my goal. (see the video below)
If you cannot see the video, please go to this link: 
(see the video below)
If you cannot see the video, please go to this link: