While not immensely popular nor common, there are nevertheless quite many people out there who flat out claim that they are in direct communication with aliens from another star system or galaxy. I'm sure that a bit of googling will give many examples.
The thing is, unlike with many other similar woo, this is something that could actually be proven with pretty much irrefutable proof... yet it just doesn't happen. (I wonder why.)
Ok, the proof wouldn't be irrefutable of the "aliens" being exactly from where the person is claiming they are from, or any other characteristics that the person may have come up with to describe them. But it would be pretty much undeniable evidence of a non-human higher intelligence.
These people always get very vague and wishy-washy messages about our destiny and future, and what we are doing to harm ourselves, and what we should be doing instead, and yada yada. Something that's extremely easy for anybody to come up with.
However, there would be a relatively easy way to actually prove that the person is indeed in contact with a higher intelligence: A correct answer to a question like "give me a proof of (or counter-example to) the Riemann hypothesis."
A correct answer would be pretty much irrefutable proof of a higher intelligence. No human has so far been able to crack this problem, but it's nevertheless something that we could verify.
And if the excuse is that the proof would be too complicated for us to even begin to understand (or, perhaps, that even the aliens themselves don't have the answer, although this excuse would be highly unlikely because these people are seldom willing to attribute any flaws to their alien "gods"), it's not like there aren't plenty of other unsolved mathematical problems, like the Goldbach's conjecture, the twin prime conjecture, the Collatz conjecture, and so on and so forth. There ought to be at least some that the "aliens" ought to be able to give a proof of.
It's rather curious that all these aliens are always happy to give vague answers to vague questions about philosophy, but never to actual questions that would prove their existence and higher intelligence.
It would also be quite curious if the aliens' mathematical knowledge would just happen by chance to coincide with ours.
(There's an "(almost)" in the title of this post because in theory this isn't exactly a 100% sure proof. That's because theoretically some person could come up with an actual valid proof, and then claim that aliens gave it to him. While this is highly, highly unlikely, especially if the person has no background in mathematics and it comes completely out of the blue, and it's unlikely that such a mathematically talented and knowledgeable person would be a ufo-believer, it's not absolutely impossible. However, if said person gave correct proofs to two different unsolved conjectures, that would be quite definitive.)