The evidence for ET and Star Wars sharing a universe is far from conclusive.

Going by strictly canon material from the movies, all we have is a picture of aliens that resemble ET from the waist up, which DVK provided a picture of.

We don't know that they resemble ET in full or taht even if they do, they are in fact the same species. It would be easy to mistake a Centari for example for a Human.

Most of the evidence for them being in the same universe comes from the extended universe or non-canon work. For example, Senator Grebleips funding a trip to another galaxy does not necessarily have anything to do with the trip made by ET.

There are enough points there that you can link things together and draw a somewhat reasonable conclusion that ET and Star Wars *may* share a universe.

Unfortunately, a clear example of Yoda existing as fiction within the ET universe would seem to void any such theory.

![enter image description here][1]

This means that any similarities between ET and an alien race in the Star Wars galaxy is just a coincidence. Star Wars is firmly fiction within the ET universe, so cannot by definition share the same universe.
  [1]: https://i.sstatic.net/ZkmjB.jpg