Type cast to Generic Type for ShowViewmodel

I am using a complex statemachine to handle certain things in parts of my app , that require state management .. however i have an issue , the ViewModel type is saved as a string. Any ideas how to turn a "Type" into the required TViewModel, i have a feeling im doing something silly and missing the point

internal void Navigate(Type viewModelType)
    {

        T newT1 = (T)(viewModelType);
       ShowViewModel<TVIEWMODEL>();
    }