>an over engineered

It’s not, that’s called a duct tape solution, which is the opposite of engineering, that’s poor design and bad practice, there are so many failure points and moving parts that it’s eminent it will fail. The engineering design should be reliable, simple, and efficient. Instead of that cluster chaos you made, you could have had a relay wired inside the bell that simultaneously trigger a normal and simple electric-based bell, so it works for you and the other person.