Step1: Add checkbox and double click on the checkbox it will create CheckedChanged event. Inside that method you can implement your logic in Step2.
Step2: Add below code to display/hide your label.
private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
if (this.checkBox1.Checked)
{
((System.Windows.Forms.Control)(lblExceeding)).Visible = true;
}
else
{
((System.Windows.Forms.Control)(lblExceeding)).Visible = false;
}
}