My house is lathe and plaster walls and hard to get wires through the walls and so I think I need to convert part of my wired doorbell into a wireless signal. I think that all I really need here would be be "wireless switches". I want the doorbell to look like any normal doorbell and not require batteries. Here is a diagram of what I want to accomplish. Is this possible? Any idea on where I would get the wireless switch parts?

(i couldnt upload image to this forum so I put the image here)
http://tinypic.com/r/1zqegya/5