Compiler error output,
1>MainFrm.cpp
1>z:\. . . . viewswitchview.h(19) : error C2143: syntax error : missing ';' before '*'
1>z:\. . . . viewswitchview.h(19) : error C4430: missing type specifier - int assumed.
1>z:\. . . . viewswitchview.h(19) : error C4430: missing type specifier - int assumed.
1>z:\. . . . viewswitchview.h(19) : warning C4183: 'GetDocument': missing return type;
assumed to be a member function returning 'int'

Comments in code specify where error is and what makes it happen, which is the including one specific include file.

Code:
//=========Here is the MainFrm.cpp file paste=============
// KEEP IN MIND, These errors ONLY occur when I add the 
// #include "ViewSwitchView.h" as shown below.

// MainFrm.cpp : implementation of the CMainFrame class

#include "stdafx.h"
#include "ViewSwitch.h"
#include "MainFrm.h"

#ifndef _ViewSwitchView_H_   // Added by me  ******************
#include "ViewSwitchView.h"  // IF I COMMENT THIS LINE ONLY, PROJECT COMPILES WITH NO ERRORS OR WARNINGS.
#endif  //_ViewSwitchView_H_ // SEE THE INCLUDE FILE BELOW AFTER THIS MainFrm.cpp, for error line.

#ifdef _DEBUG
#define new DEBUG_NEW
#endif

// CMainFrame
IMPLEMENT_DYNCREATE(CMainFrame, CFrameWnd)

BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)
 ON_WM_CREATE()   
END_MESSAGE_MAP()

static UINT indicators[] =
{ ID_SEPARATOR,           // status line indicator
  ID_INDICATOR_CAPS,
  ID_INDICATOR_NUM,
  ID_INDICATOR_SCRL,
};

// CMainFrame construction/destruction

CMainFrame::CMainFrame()
{// TODO: add member initialization code here
}

CMainFrame::~CMainFrame()
{
}

int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{ if (CFrameWnd::OnCreate(lpCreateStruct) == -1)
         return -1;

  if (!m_wndToolBar.CreateEx(this, TBSTYLE_FLAT, WS_CHILD | WS_VISIBLE | CBRS_TOP
      | CBRS_GRIPPER | CBRS_TOOLTIPS | CBRS_FLYBY | CBRS_SIZE_DYNAMIC) ||
      !m_wndToolBar.LoadToolBar(IDR_MAINFRAME))
   { TRACE0("Failed to create toolbar\n");
	return -1;      // fail to create
   }

  if (!m_wndStatusBar.Create(this) || !m_wndStatusBar.SetIndicators(indicators,
      sizeof(indicators)/sizeof(UINT)))
   { TRACE0("Failed to create status bar\n");
         return -1;      // fail to create
   }
  // TODO: Delete these three lines if you don't want the toolbar to be dockable
  m_wndToolBar.EnableDocking(CBRS_ALIGN_ANY);
  EnableDocking(CBRS_ALIGN_ANY);
  DockControlBar(&m_wndToolBar);

  return 0;
}

BOOL CMainFrame::PreCreateWindow(CREATESTRUCT& cs)
{ if( !CFrameWnd::PreCreateWindow(cs) )
      return FALSE;
  // TODO: Modify the Window class or styles here by modifying
  //  the CREATESTRUCT cs
  return TRUE;
}

#ifdef _DEBUG
void CMainFrame::AssertValid() const
{ CFrameWnd::AssertValid();
}

void CMainFrame::Dump(CDumpContext& dc) const
{ CFrameWnd::Dump(dc);
}

#endif //_DEBUG

// CMainFrame message handlers
// There are none at this time. 
//=============End of MainFrm.cpp file===========================

//==============include file paste===============================
// ViewSwitchView.h : interface of the CViewSwitchView class
//
#ifndef _ViewSwitchView_H_
#define _ViewSwitchView_H_     // Note this does not prevent error
#endif //_ViewSwitchView_H_   

#pragma once

class CViewSwitchView : public CView
{protected: // create from serialization only
 CViewSwitchView();
 DECLARE_DYNCREATE(CViewSwitchView)

// Attributes
public:
 CViewSwitchDoc* GetDocument() const; //<-- this line (19) flags the error if I include this 
                                     // file in MainFrm.cpp, even with the ifndef's above
// Operations
public:

// Overrides
public:
 virtual void OnDraw(CDC* pDC);  // overridden to draw this view
 virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
protected:
 virtual BOOL OnPreparePrinting(CPrintInfo* pInfo);
 virtual void OnBeginPrinting(CDC* pDC, CPrintInfo* pInfo);
 virtual void OnEndPrinting(CDC* pDC, CPrintInfo* pInfo);

// Implementation
public:
 virtual ~CViewSwitchView();
#ifdef _DEBUG
 virtual void AssertValid() const;
 virtual void Dump(CDumpContext& dc) const;
#endif

protected:
// Generated message map functions
protected:
  DECLARE_MESSAGE_MAP()
public:
};

#ifndef _DEBUG  // debug version in ViewSwitchView.cpp
inline CViewSwitchDoc* CViewSwitchView::GetDocument() const
   { return reinterpret_cast<CViewSwitchDoc*>(m_pDocument); }
#endif
//-----------end of include file---------