use this code for wireframe, works for models and levelgeometrie

material wireframe //change the name in the Texture name, if you want to use it for levelgeometrie
{
effect="
DWORD wfcolor = 0xFFFFFFFF; // Change this to the wireframe color of your choice
technique wireframe
{
pass p0
{
TextureFactor = <wfcolor>;
// CullMode = None; // Uncomment if you want backface too.
FillMode = Wireframe;
ColorOp[0] = SelectArg1;
ColorArg1[0] = TFactor;
}
}
";
}


and write in your action of the model:

action blabla
{
my.material = wireframe;
...
}

if you want it for models.

hope that helps