Abduction delusion: Strange lights in the sky that appear at night in a certain place. Then the light touches a person, the person falls unconscious. Hours later, the person wakes up and claims to have memories pertaining to an alien abduction, despite not actually going anywhere. Foundation later intercepts a broadcast from unknown source. The transmission is is an unknown language, but the word "preparedness" is translated.
Death?: Original description: Artifact that causes person to die painfully. Revision: Artifact that causes people to think that the subject has painfully. The subject may no longer interact with people who think the subject is dead, or the things they interact with. As news of their "death" spreads, the subject slowly becomes incorporeal, before fading away
Helper bots: Collective of robospiders that steal pieces of technology. Uses technology to repair ship for an extraterrestrial trying to escape Earth. The extraterrestrial is already dead. Foundation finds message that shows the extraterrestrial was a scout, and attempted to leave Earth after finding Site-██, but was killed by SCP-████. The alien recommended Earth for destruction, because of anomalies present. It is unknown if the transmission was sent.