Want smart lights and fans but love the switches you already have? A smart WiFi switch module is the answer. It's a small relay that sits behind your switchboard, invisible from the front, and makes your existing switches controllable by app, voice, and schedule. Nothing on the wall changes. Here's everything you need to know.
What Is a Smart Switch Module?
Also called a retrofit smart switch or smart relay, it's a compact WiFi/Bluetooth module wired between your switchboard and the loads (lights, fans). Each "node" on the module controls one load. Flip the physical switch and it still works; tap the app or say "Alexa, turn on the fan" and the module does it for you.
Why Choose a Hidden Module?
- Keeps your existing switches and plate — no change to the room's look.
- Works with any brand of switchboard (Anchor, Legrand, Havells, etc.).
- Cheapest way to automate a full room.
- Reversible — ideal for renters.
It's one of the three ways to make a board smart — compare all three in 3 ways to make any switch board smart.
Choosing the Right Node Count
| Module | Controls | Best for |
|---|---|---|
| 1 Node (16A) | 1 heavy load | Geyser, AC point, motor |
| 2 Node | 2 loads | Bedside board, small room |
| 4 Node Mini | 4 loads, 2-module size | Tight or small switchboards |
| 4 Node | 4 loads | A typical bedroom |
| 8 Node | 8 loads | Living room / large board |
Count the lights, fans, and sockets on the board, add one spare, and pick the module. Need fan speed control? Choose a fan-capable module — see how to make your ceiling fan smart.
WiFi + Bluetooth: Why Both Matter
AZIOT modules use WiFi for remote and voice control and Bluetooth as a reliable local fallback if the network drops. See WiFi vs Bluetooth switches.
How It's Installed
- Switch off the mains.
- An electrician wires the module's inputs to your switches and outputs to the loads, inside the back box.
- Close the plate — the module is fully hidden.
- Pair to 2.4GHz WiFi in the app and link Alexa/Google.
Full wiring steps are in our wiring guide for beginners. Most modules need a neutral wire in the box; ask your electrician to confirm.
Is It Right for You?
If you want automation without changing the look of your home, or you rent, a hidden switch module is the best first step. If you'd rather have a premium touch finish, consider modular touch switches instead — our smart switch buying guide compares both.
Automate invisibly: browse AZIOT smart switch modules in 1, 2, 4 and 8 node sizes.