It depends on what you are trying to do!
If this is wire that is not being used, you could use the gauge on your wire snips to find out.
Now, If this is wire that is in use or if you do not own wire snips, you probably should not be touching the wire!
Please do not take this the wrong way but, when it comes to the stuff that can kill you, burn your house down (hours later), or ???, I only advise people to use a licensed electrician.
Maybe you could repost with more information about what you would like to do. Give as much information that pertains to this project.
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