a round wall plate 50mm in diameter with a 25mm opening - Interlocking pieces break apart into two halves for reassembly around existing cables

thingiverse

This consists of two interlocking pieces which break apart and can be reassembled around existing cables, to give a somewhat tidier appearance. For a cleaner look, I skipped screw holes and taped mine in place with double-sided adhesive (sticky-tack putty is also an alternative and might be more paint/wallboard friendly). *** Update on tape vs sticky-tack: I'd recommend using sticky-tack putty, as the double sided adhesive tape I used let go of the plastic after a day or so, while the sticky-tack is still in place. Plus the tape was a bit of a PITA to remove from the wall. You might want to use the V2 file which provides for a bit more space between the two pieces, as the V0 version can be difficult to initially break the pieces apart after printing.