Galip thinks that by living as Celal he can figure out how Celal thinks and locate both him and his wife, so he takes up residence in Celal's apartment, wearing his clothes and eventually writing his column.
Galip believes that by adopting Celal's persona, he can comprehend Celal's thoughts and locate both him and his wife. He then moves into Celal's apartment, wearing his clothes, and eventually begins writing his column.