Previous answers don't account for the fact that you've overloaded the equals operator and are using that to test for the sought element. In that case, your code would look like this:
list.Find(x => x == objectToFind);
Or, if you don't like lambda syntax, and have overriden object.Equals(object) or have implemented IEquatable<T>, you could do this:
list.Find(objectToFind.Equals);