Hardwire Ring Doorbell 2---Where Do You Store the Resistor

Hi, I have a Ring Doorbell (2nd generation) that I'd like to hardwire. I don't have an existing doorbell, so I will need to include a resistor. My question is where I should store the transformer and resistor. I have an empty receptacle (galvanized steel?) in the wall near the doorbell, but don't know whether its safe to put the resistor there giventhat it can get quite hot. Any advice? None of the DIY videos that I have seen talk about where to secure the transformer or resistor.