My front wheel has started to wobble a bit at the hub and it's most noticeable when braking at the lights, as the front wheel is doing like a "pulsing" sound when braking - like as if the wheel is off center. I've pulled the hub apart, but I cannot see any obvious issues, yet when I lift the front wheel off the ground, as it's attached to the fork, the wheel slightly shakes when I tap it. It is not firm as it should be.
Because I cannot see obviously what's going on, could the bearings inside the sealed-cartridge have worn down in size? There is ample grease on them, but I guess even over time wheel bearings do wear down a micro-millimeter or two? That's the only explanation I have as to why the wheel hub has a slight wobble / shake.
Wheel is Campagnolo Vento-Reaction, about 5 years old now.
Here's a video of the wheel, showing how to get to the hub bearings...