[CameraRig] Wireframe Visible during Runtime in Game View

Recently there is an annoying wireframe of the Steam VR (v1.2.0) Play Area visible during runtime in the Game view window (on the headset everything is normal looking). I also see a wireframe on (or offset from) my hand controller. I'm using VRTK (v3.0.1) also.

I think I must have accidentally changed a Unity display setting or some other setting. Perhaps this is a Unity interface question and not a VR question. But if I create a new scene without a SteamVR camera rig, then i don't see any odd wireframes in the game scene view during runtime.

Sorry if this is obvious! Thanks for your help.