Replacing an Intermatic EJ351 mechanical light switch timer with a wifi Smart Switch KS-602 timer in 1935 house
From your description, it sounds like the green wire is live, the black wire is connected to the entry light and the red wire is connected to the patio light. There is no ground or neutral coming to the box. The EJ351 timer switch is specifically advertised as not requiring a neutral connection.
Try turning on either light and then measuring the voltage on the black/red wires. These wires will now &quot;appear&quot; to be hot wires since they will be connected to live through the switch. When the lights are off the wires will &quot;appear&quot; as neutral since there is a (relatively) low-resistance path to neutral through the lights. They are the switched hot wires going to either light.
You cannot use your smart switch without a neutral wire.