I seriously used to think that the random noises made by the old plumbing in our house would just happen to be interpreted as alien speech by some nearby aliens and they would come to investigate and GET me.
Looking back on this one, I'm amazed not by how silly it was (after all, I was a kid at the time) but how amazingly complicated it was.
A childhood belief about aliens

others believed things like this
- I thought the ball-headed person in the Bic logo was an alien and communicated using alien-like noises.Anon
- i thought aliens would come to earth year 2000 because of a commercial were an alien ate a hot dog— ulle
- On TV game sows when they said the winners were chosen "at random" I thought random was a town.Anon
- When I was a kid I used to believe that my perent's were aliens and I was the only human in the house.— Ali
- I used to think that a con artist was someone who was really good at making complicated art.Anon
- I once believed that the walls and ceilings were completely jam packed with plumbing and wiring.— David