I am attempting to wire a second doorbell. I read in your column that you should wire the two doorbells together. However, I cannot snake a wire to my first doorbell. The second doorbell is located at the button that was once on the outside of the house. Can I wire my second doorbell into the first doorbell at this point and then extend the wires from both doorbells to an outside button. Please answer asap, as I am in need of wiring this in order to complete construction

Yes. You may need to use three wire or two 2 wire cables.