We had another brand fridge in the house that did that. The "ticking" was the defrost cycle and probably just the expansion of materials as the fridge warmed up briefly. In any case, it was considered "normal".
Icemakers have been know to "tick" during their cycle too, usually when getting ready to dump ice into the bin. If it's on, try turning it off and see if the ticking disappears.
I'm not familiar with your Ventana, but there is bound to be some screws holding that wedge in. Maybe under wooden caps. Hunt around and they will become evident.
Former owner of 2004 American Tradition and several other RVs
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC