private System.Threading.Thread aaa;

  private void Run()
        {

            aaa = new System.Threading.Thread(Process_start);

            aaa.Start();
    }

  private void Process_start()
        {
            while (true)
            {
                DoSth();
                System.Threading.Thread.Sleep(10000);  
            }

        }

namespace Test
{
    class Program
    {
        private static void Main(string[] args)
        {
             System.Timers.Timer timer = new System.Timers.Timer();
             timer.Interval = 1000;
             timer.Elapsed += new EventHandler(timer_Elapsed);
             timer.Enabled = true; 
        } 
        private void timer_Elapsed(object sender , EventArgs e)
        {
             //do something 
        }
    }
}