I'm gonna have to agree with Cloned on this one. The chance for another alien civilization to exist so close to us is downright asinine. It's easy to make a statement using the retroactive historical conjuncture that led to our civilization & extrapolating this to other worlds, but you really must think of it in much, much more ancient terms.
It's not just "there's a chance that there are other civilizations equivalent to ours within galactic skipping distance of us just because they probably have life & liquid water."
It's that there has to have been planets suitable for life that also developed multicellular life in such a proportion that land/semi-aquatic animals with multiple gripping appendages evolved far enough to develop sapience and had the exact right environmental pressures to push them towards advanced tool usage & language to give them the opportunity to develop organized civilizations along a specific set of biomes that develop in a specific way that eventually leads to these animals developing & using radio technology for a long enough period of time that their transmissions are noticeable.
You can fudge the probabilities in many different ways: maybe this planet's life developed dominant pseudo-mammalia before xeno-reptiles evolved; maybe it's a superhabitable planet that has always been "optimal" for sapient life (which might backfire for a variety of reasons); maybe a non-humanoid creature similar to a corvid developed opposable thumbs... But there are 10,0004 ways it all could've gone horribly, horribly wrong at any point in their planet's history.
It all went horribly right in ours, and yet we're still not out of the woods until we reach a safe Singularity scenario. It's possible that something playing out differently 1,000 years ago (like a single peasant losing instead of winning a drunken tavern bet somewhere in the ass-end of Germany) wound up leading to humanity dying off in the 1800s from some super-charged Black Death. Or, conversely, led to us developing digital computers in the 1700s.
The point is that the variables are so extreme that the likelihood of another advanced technological civilization existing anywhere nearby is infinitesimal, even if life exists nearly everywhere around us.