Using Arduino as a switch

Hello everybody
I would like to make a very simple project on Arduino: connect two wires to two analog/digital pins, and when I receive some trigger from an external device (like a phone, via wifi), make a link between the two wires. Just like a simple switch. I have an arduino device and the arduino wifi shield.
I would like to know if this is feasible and if so, how to do that.
Thank you very much,

make a link between the two wires. Just like a simple switch.

What is it exactly that you are trying to do ? You have presented a possible solution but from the way that it is phrased you do not know much about the Arduino.

What is the project intended to do ? There may be alternative ways to do what you want.

hackchoc22:
Hello everybody
I would like to make a very simple project on Arduino: connect two wires to two analog/digital pins, and when I receive some trigger from an external device (like a phone, via wifi), make a link between the two wires. Just like a simple switch. I have an arduino device and the arduino wifi shield.
I would like to know if this is feasible and if so, how to do that.
Thank you very much,

You can't do it directly, but you could use a relay or possibly a CMOS switch IC, operated by the Arduino.

As Bob asks, what is the goal?

The goal is very simple, just like you have a switch to light a room, i would like to create a "wifi switch" with the arduino: instead of pressing on the button, activate the light remotely from my phone.

hackchoc22:
The goal is very simple, just like you have a switch to light a room, i would like to create a "wifi switch" with the arduino: instead of pressing on the button, activate the light remotely from my phone.

Is it low-voltage DC or mains AC? How much current does it draw?
Is it an existing light or one that you're making?
(Even a LED is a light.)

A relay might be your best bet, but without full information it's hard to say.

search this list, there are free apps that you can use to control the Arduino from a cell phone.