There certainly are. However, I am not talking about microbe sized beings living in those planets where there might be traces of water or an Earth-like atmosphere. I’m referring to consciousnesses whose physical bodies are so subtle that they cannot be perceived by our naked eyes.
Have you tried looking at the Earth’s magnetosphere? Surely it wasn’t very easy for your eyes, unless you were in the north pole during winter. Have you tried seeing someone’s aura? If you are a medium or even if you meditate on a regular basis, you may see a thin, translucent wave, like those when the heat makes the horizon look like it’s water rocking.
Some “extra terrestrials” do dwell in bodies of such nature, and most of them – at least in this galaxy – in much lighter bodies. The frequency in which they live is different of the one we experience in this planet, so a dense physical body, with animal instincts is not of use for more evolved creatures.
Many other consciousnesses do live in lower frequencies than the one of the Earth, and their physical size and appearance can be paralleled with the ones of viruses, bacteria and other beings in far away galaxies.