Why does my central air running raise the humidity in the house? Does it need serviced?

ummm. yea...

Go up into the attic and see if the drain for the chill coil is working. If you have water being extracted from the chill coil and water going down the drain, your cool air is being dehumidified. Your unit may be too big for the house and so you are reaching cold temperature before all the water can be extracted. That would be incorrectly sized equipment.

Do you have a central humidifier? They are often connected to the fan relay and need to be shut off in the summer. The solenoid can also get stuck in the open positions so you need to shut off the water valve to them also. Another reason they seem to raise humidity levels is when the drain pan becomes clogged and fills with water, can also damage the furnaces and such when that water leaks through the unit. You also have to take into consideration how high the humidity level are at the time. Often the air conditioner doesn't run long enough to remove enough humidity while still maintaining temp, that is when you also need a dehumidifier in the system. Air conditioners themselves, lower the humidity levels, remove water from the air. If it isn't, there is a reason.

seems likely -- it should be lowering the humidity

The A/C may need serviced, but even if it is seriously malfunctioning, it IS NOT raising the humidity.

Yes it needs to be looked at it should not raise the humidity .

Yes. Central air should REMOVE humidity.

it should decrease the humidity, it may however make some surfaces very cold so they squeeze more water out of the air as condensation, does it blow on any metal things?

Yes

Because it needs to be serviced

It shouldn’t raise he humidity in your home