You can try this quick script hack… If the viewport is neither in wireframe or shaded (like say ghosted), it will set it to wireframe. It could also be changed to just ignore your request if the viewport is in neither of the two modes…
–Mitch
Option Explicit
'Script by Mitch Heynick ©
'Version 3 February, 2014
Call ToggleWireframeShaded()
Sub ToggleWireframeShaded()
Dim currView, currDMode
currView = Rhino.CurrentView()
currDMode = Rhino.ViewDisplayMode(currView)
If Not IsNull(currDMode) Then
If currDMode = 0 Then
Call Rhino.ViewDisplayMode(currView, 1)
ElseIf currDMode = 1 Then
Call Rhino.ViewDisplayMode(currView, 0)
Else
'Current view mode is neither wireframe or shaded
'Set view to Wireframe mode
Call Rhino.ViewDisplayMode(currView, 0)
End If
End If
End Sub