When do I use the In-Wall Dimmer/Switch or Wall Dimmer/Switch ?
If you want to keep your current switch, then please use In-Wall devices. They are installed inside the switch box. For new or fast installation, we recommend using Wall Dimmer/Switch which replace your current switch.
Do I need to install the neutral line ?
Yes, you do. You can get the neutral line either from the light bulb or from the nearby power outlet.
Can SA-102 be used to control the lighting or the power outlet ?
Yes, you can. The SA-102 can be a light switch or power outlet switch.