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 that 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.
On the other hand, a clear example of a mask of Yoda is seen in E.T. This could void any theory on sharing a universe, but could also simply be an easter egg to help viewers make the connection.
![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
