We're going to assume if you're reading this, you are not a contractor, an electrician or an engineer. (Or at least we're going to hope that, because you probably already know your stuff.) Anyway, if you're still interested in tearing down your wall yourself, and you've gotten the go-ahead from engineers, electricians, etc., you next you need to do some investigating before diving in. Put the sledgehammer down and back away slowly.
It's critical to know what lurks inside the wall you want to take down, and again, it's important to have an expert on hand to determine this. There are obvious signs that a wall it is not just a wall -- like a light switch, a vent or a thermostat -- but even lacking features like that, you never know what's tucked inside.
There are some tools of the trade that can be used to give you a clue, though. An A/C voltage detector or a voltmeter, for example, can be used to test whether any electrical juices are flowing. Walls need to be scanned thoroughly to ensure conditions are safe to start the job. If you do find an electrical signal, much more care must be given to the task.
Once everything is squared away and you have a good read on the situation, it's time for the real work to commence.