My doorbell rings as long as somebody pushed the bell bush. I measured 10V ac while ringing at the doorbell contacts. Now I would like to use this ac in parallel to connect two cables as long as the bell push is pushed, just like the bell push was potential-free.

How can I achieve this?

I am sure there are components which can do this and I would be able to put them together if somebody told me what I need and how to connect it.

**Edit**

Sorry for my English, it's not my native language. I had to look up many technical words, and probably I picked the wrong ones. Feel free to edit, please.

Further clarification:
What I want the bell push to do at the same time is:

 1. Let the doorbell ring. That is currently the case. The doorbell closes a 10V ac circuit
 2. Close another circuit, which it independent from the first one. Is just needs to be closed.