The only such thing I'm aware of is The Effectiveness of AI Existential Risk Communication to the American and Dutch Public.
Robert Miles has been making educational videos about AI existential risk and AI alignment for 4+ years. I've never spoken with him, but I'm sure he has learned a lot about how to communicate these ideas to a general audience in the process. I don't know that he has compiled his learnings on that anywhere, but it might be worth reaching out to him if you're looking to talk with someone who has experience with this.
Another resource - Vael Gates and Collin Burns shared some testing they did in Dec 2022 on outreach to ML researchers in What AI Safety Materials Do ML Researchers Find Compelling? . However, I should emphasize this was testing outreach to ML researchers rather than the general public. So it may not be quite what you're looking for.
Does anyone know who is testing AI Safety public outreach messaging? Or where I can find relevant research on this?
Things that would be interesting to test:
It may also be worth considering channels too. I.e. outdoor vs social vs audio vs OLV but that is a separate thing.
Thanks!
Yanni