Here's Lucy
Lucy and the Little Old Lady (4x17)
:
When an old lady comes in the enployment agency looking for a job because she has nowhere to go, Lucy decides to let her stay at her house. When Mrs. Brady sells land to Harry, Kim tells them about a similar sounding scam which gives Lucy and Harry the idea to let the Mrs. Brady have a seance in which they dress up as Napoleon and Josephine to convince her to refund Harry his money.