Thanks for the information all of you. The sensor didn't appear to have any wires running to it. Next week I'll be able to spend more time with the manual and read it in-depth. I never considered the possibility that it could be running on carrier current. If I can remember I'll respond back with what I found just for your FYI.
"¿Que es la frecuencia, Kenneth?" (Be sure his name is actually Kenneth...)
Could you just imagine all the members of R.E.M. playing a concert wearing those big ol' sombreros.