ASP.NET MVC Scaffolding Template Files (T4)

The following is where you can find the T4 template files used by ASP.NET MVC Scaffolding:

Visual Studio 2015:
C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\Extensions\Microsoft\Web\Mvc\Scaffolding\Templates\

Visual Studio 2017:
C:\Program Files\dotnet\sdk\NuGetFallbackFolder\microsoft.visualstudio.web.codegenerators.mvc\