ruby undefined method error

I get the following error below with the attached ruby script and text file. Please note you will need to include the text file in the command line after entering the ruby file name. I tried referring to the variable 'mystery_word' in the script as an array but get the same error. Please help. Thanks.

'hangman.rb:47:in `<main>': undefined method `each' for "<mystery word>":String (NoMethodError)'
ruby_hangman.txt
wordsHangman.txt