Yes, Send them an email, Notify them with that incident. If you have time/day to display better it is. Good luck
While working on my sites I've clicked on an ad once. They know it is an accident and won't punish you, most likely if you were logged into Gmail, that click wasn't even counted. If you make it sistematic though it will become a problem, obviously.
you definitely should send and email telling them when did it happen ie the time, day and how it happen. It would always help to be honest with them. At least that is my opinion. Thanks JulieV
The best place to get answers to questions like these is the official Adsense help pages. Here is the answer to your question: https://www.google.com/adsense/support/bin/answer.py?hl=en&answer=62472#q1
It surely might be good to let them know, but this must happen very often. Think about businesses with 50 employees. Some employees working or visiting the company's website must accidentally click the ads sometimes. Do they get problems? You can also check the AdSense questions and answers section. I saw a related section some years ago.
Best thing you can do is to email them or contact them and inform them of the accidental click while you are doing some maintenance of your site. Shelly77
Don't worry, one click is ok. I have clicked on my adsense ads several times during 3-4 months, and nothing happened. So don't worry, man.