Cloned Cube is a Portal mod. It takes place after GLaDOS' fall in Portal. You assume the role of Chell's secret clone. You have to escape or else you may just be tested to death. There is one obstacle. CUBiS is trying to kill you.
Two alarms that you see popping out of the wall in cc_1. One is for security breaches while the other is for fires. It fixes up the whole inconsistencies of why there were emergency lights sticking out of the wall when you didn't even see any originally in Portal.