I got wireless gear too, but I don't have this problem - unless I play from my neighbor's house. Try switching on wired for a moment and see whether this still happens.
It's possible that you need to either charge your stuff, mount the wireless receiver on an USB 3.1 port (extra power) or reduce the (possible) interference with your wireless setup.
Now, there's this other type pf mouse lag, on systems with Nvidia cards. If you have such a video card, go to the Nvidia control panel and turn off V-sync for Freelancer.exe. Under normal circumstances (= if your wireless gear is 100% functional), this would reduce the slightly delayed actions in the game.