I am not a smart girl. I just purchased a 1900's home with gas heat and electric air conditioning. The thermostat that was in the home was a Hunter - model 40135 with the HG switch on. The thermostat that I am trying to replace it with is a Honeywell RTH8500 wifi series. Unfortunately I got ahead of myself and did not label the wires. There are four wires coming out of the wall. Red, white, green, and yellow. There was an additional small red wire that isn't connected to the wall at all. Any help would be greatly appreciated. Thank you so much!!