Cornelius Cretu
If you only have two wires connected to the switch, it means there's no neutral there, so you can only install certain types of timer switches or you will have to run a permanent feed to the switch in order to install more sophisticated timer switches. The types of timer switches you can still install are the "pneumatic time delay switch" or a "2 wire PIR activated timer" The wires you're talking about are the permanent Line and the Switched Line. There's no positive wire in alternative current.