Sounds like a country song, "I go stalking, after midnight.." In all seriousness, don't go that route. Will only drag you down and hold you back from moving on from her, which it sounds like it's time to do. You are being serious here, right, or is this just a joke?

Pointless, just hurtful to you. Spend your money on a good lawyer...interview a couple!

Wrong. Just really really wrong. What good will it do you to know anyway. Think the best of her and try to move on.

Yes it is wrong. Im guessing your paranoia and mistrust contributed to your separation. If its over, let it go and start living your life. I spent three years separated before divorcing. Amiacable divorce. We're best friends now.

Take it from someone who’s been divorced
Let her go!!
I say this if you cross the line she could take your freedom and is anyone really worth that?

Definitely wrong. If you don't trust her as it is, spying on her certainly is not going to lead to greater trust, so unless you're looking to make that separation a definitive divorce, stay away from the gadgets and put your energy toward what it is you want as a result of the situation.