I would expect that you heard somebody in a neighboring cabin.
Your dining room stewards where trying to be friendly. They probably have never been on deck 6 and wouldn't know if it was haunted. But you gave them something to talk about with their friends.
A Bad Day At Sea [with power] Always Beats A Good Day At Work
Carnival: Glory 2004, Destiny 2008, Splendor 2009, Freedom 2011, Valor 2012, Dream 2013
Celebrity: Summit 2011
Princess: Ruby 2010, 2014, Caribbean 2013, Coral 2014