Dust In Viewfinder
Remove the lens and point a Rocket Blower (or alternative) upwards to blow out the spec.-- hide signature --
I have done this several times with good results. Just hold camera with mount facing down and give a puff of two with a rocket blower. Never had a problem blowing dust into the sensor.
While doing it that way the sensor is covered anyways. And unless it is a sticky bun, a sensor cleaning cycle will get rid of it.
Some cameras, some lenses, some computers