Switching lights by Harry Potter themed voice commands I'd like to know whether I can make the light in a room light up just by saying two voice commands. Specifically lumos and nox spells, like in Harry Potter. I have never worked with Arduino or with any programs it uses, but I have an idea how it should work. I watched some tutorials and read a bit about it, but I'm not entirely sure, if it will work and what exact types of Arduino components would be most suitable for it.

I'm thinking about connecting the voice command module's output directly to the light switch. But I don't know if it would be better if the Arduino would just somehow switch the light by enabling the current to flow or flipping the switch with a servomotor directly.

I also don't know if the module can work by itself when just plugged into the wall. If it has to be still plugged into a PC, that would be useless.

I'd also like to know which Arduino (or components in general) I should use and if the microphone could sense the commands from like 2-3 meters.

I really am thankful to anyone, who would be so kind and help me with this idea, because it should be a gift for my younger sister, probably the biggest Harry Potter fan in the world.
This might be a hard project to start with.

First, you need to process the 'voice' from the microphone. This will be probably impossible on an Arduino.

Than you need to program everything, can be quite complicated (for a beginner). 

Making something respond to 'any' sound is easier and can be done by Arduino and limited programming. Voice recognition is completely different.