I remember going to Magic Kingdom 3 years ago and seeing a building where Mickey mouse characters were. what is the name of that building and what is it located by?
I think it might have changed since you were there 3 years ago because most of their construction is done. Right now you can meet Mickey and Pals in Town Square at the Magic Kingdom. You could also use one of your FP+ to see them. It depends on how long you would like to stand in line.
Currently at MK - Mickey meets by himself in Town Square Theatre. Goofy, Donald, Minnie and Daisy (in various Circus Sideshow costumes) meet at "Pete's Silly Sideshow" in the new Storybook Circus area (where Mickey's Toontown used to be). There is one line for Goofy & Donald and one line for Daisy & Minnie. I think Pluto still meets by the flagpole at the front of Main Street.