There is a scam on Google Adsense going on.
The scammer sends a link and includes a message stating;
Invalid click activity detected on your YouTube channel. If you would like to appeal this decision and want your account to be reviewed again, click the link below to complete the form. Otherwise, your Adsense and YouTube account will be suspended due to invalid ad click activity.
Please, do not click on any link.
If you suspect otherwise, sign into your account and check your account directly.