Plastic feeling piece covered in sticky black grease that fell off my Van when I opened the door.

Not sure sure if this fell on top of my van or is maybe a piece of the door. Not exactly sure where it fell from since it just kind of plopped down when opening the door. The van is a 2018 Honda Odyssey. The grease stuff is really messy and kind of sticky, but washes off with dawn power spray. Operation of the door seems normal.