If you've been okay for 4 years and suddenly got a spike in your earnings, then I wouldn't be too worried about it.
Watch and see if it levels out after another week.
Do keep an eye on your traffic though and make sure you're not getting a lot of bot traffic. Someone could have a bot clicking on your ads to try and ban you or they could just be manually clicking on your ads.
If you're really worried you could remove some of your ads for awhile.
10% ctr is pretty high and would get me worried, but 20% would certainly have me worried if it lasted for a long time.