A bit more efficient:
14.times.map { rand(33..126).chr }.shuffle.join
14.times.map { rand(33..126).chr }.shuffle.join
At any rate, would probably want to use https://ruby-doc.org/stdlib-2.5.1/libdoc/securerandom/rdoc/S... for password generation.
Also, I think you might just want an alphabet and use sample: https://ruby-doc.org/core-2.5.1/Array.html#method-i-sample
# unsure if you need a:
require 'securerandom'
(33..126).sample(14, random: SecureRandom).map(&:chr).join