private void ics_CustomObjectReceived(string fromuser, string customobject)
{
var doc = new XmlDocument();
doc.LoadXml(customobject);
var reader = new XmlNodeReader(doc.DocumentElement);
var ser = new XmlSerializer(typeof (Person));
object obj = ser.Deserialize(reader);
// Then you just need to cast obj into whatever type it is eg:
var personReceived = (Person) obj;
MessageBox.Show("Received => " + personReceived.Name);
}