Alternative ways to unlock doors is a favorite hackerspace way to pass time. Most engineering colleges give students special priveleges when accessing engineering rooms. This is part of engineering ethics. Some colleges require doors to be closed due to fire code, yet have centralized control over when they lock and unlock. The result is that classrooms are locked when students try to get into them for class. (Lots of things don't make sense). So the question is how do students get in the room? There are several fun solutions that are more complicated than covering the door jam with tape. One is hacking the current system, overriding it during scheduled times and letting the centralized chaos do their thing. Perhaps the solution will be to purchase a pet sensor door and reuse its parts.