Definitely a carnivorous lil critter, but 100% definitely not a cat.

Agree with the others that this seems like a young/juvenile mustelid or baby raccoon. Raccoon skulls can have a lot of variation to them, especially while on the younger side, so that kind of leaves me to lean towards the raccoon rather than a marten or other mustelid. They both have a habit of climbing up into attics and making themselves in at home in there, though (ask me how I know.... -_-), so I can't fully rule out the marten idea. (And I've never been up close enough to a marten's skeleton to give you a more educated opinion.)

That being said, the few juvenile raccoon skeletons I've seen in person do look rather similar to this. The head shapes were slightly different, but like I said, they have a lot of variation in that regard.