You don't need to rewire your home to control your lights by voice with Alexa. You simply need to buy smart LED bulbs that can connect to WiFi or a smart hub that's compatible with Amazon's Echo.
With Alexa and your voice, you can turn the bulbs on or off. If your smart bulbs are dimmable, you can also use your voice to set their brightness, and even change their color if the bulbs you bought supports colors!
If you'd rather not buy smart bulbs, you can use Alexa-compatible dimmers and switches to control your home's lighting.
You can find a bunch of dimmers and switches compatible with Alexa here. Note that not all dimmers and switches in the link are compatible with Alexa, make sure to look for "Works with Alexa" in the product name or description, and whether it needs a hub to work with Alexa.
Smart outlets plug right into your regular outlets, and you can plug pretty much any device to the smart outlet itself to turn those devices on or off with your voice. You can also set the smart outlet to turn on or off on a schedule, too.
For smart doorlocks, you'll need a smart home hub compatible with Alexa from companies like Vivint, Securify Almond, Lutron, Samsung SmartThings, Nexia, and Wink that works with the smart lock of your choice.
However, due to security, you can't ask Alexa to unlock your doors. Alexa has amazing voice recognition, and all it takes is a tech-savvy burglar to shout at Alexa from outside to unlock your doors.
If you have a smart alarm system, you can ask Alexa to arm the alarm.
Yet, Alexa won't disarm your alarm for the same reason it won't unlock your doors.
Smart thermostats don't need any special installation. You can use the existing wiring behind your old thermostat, then connect it to your WiFi network or its respective smart home hub.
With your Amazon Echo with Alexa, you can turn your TV on, off, change the volume, and switch channels.
To do so, you'll need a specific hub designed to work with entertainment devices. Logitech's Harmony remote/hub (or just the hub) is compatible with Alexa and a popular choice for controlling your various entertainment devices with a single remote.
Another good choice is the AnyMote Home hub, which is also compatible with Alexa.
Control your appliances.
For smart fridges, you can ask Alexa to add something to your shopping list and even place an order for groceries, all without having to tap your smart fridge like a giant tablet.
For smart washer/dryers, you can ask Alexa to start a cycle and how long is left until it's done.
There are even smart ovens you can ask Alexa to preheat or turn off, as well as smart window air conditioners and water heaters, too.
GE already has a few appliances that work with Alexa, and Whirlpool recently announced new appliances that will be compatible, too.
Use Alexa for your car.
Ford and Volkswagen recently announced at CES 2017 that they will integrate Alexa into their cars. Ford's integration will come during the first half of 2017, but there's no timing for Volkswagen yet.
That means you could control your home, like lighting and temperature, from the comfort of your car using your voice. And that's great because turning on your car's lights and setting the temperature with an app is likely to distract the driver.
Eventually, you'll also be able to use Alexa from home to lock/unlock, start your car, and set the climate control.
Yep, ceiling fans.
Fan, lighting, and HVAC company Haiku teamed up with Amazon to let you control its ceiling fans speeds and lights with Alexa.
The Amazon Fire TV's remote has Alexa built in.
The Amazon Fire TV's remote, which comes with the Amazon Fire TV stick or Amazon Fire TV streaming box, comes with Alexa built in, so you can do everything you can do with the Amazon Echo without the Echo device itself. That also includes controlling the Fire TV so you can open apps to play video and music.
The main difference is that you have to press the microphone button on the Fire TV remote itself to activate Alexa, whereas with the Echo you can activate Alexa by simply calling it with your voice. The Fire TV and remote themselves also don't have built-in speakers, so your music will come out of your TV speakers, or an audio system that's connected to your TV.