add_service.rb

# Vista
a href="/services/jobs/new" data-behavior="add_service"

# Routes
get '/services/:root/new', to: 'services#new'

# Controller
def new
  render partial: "services/new_#{params[:root]}"
end

# Behavior new_service
$.ajax({
  type:     'GET',
  url:      container.prop('href'),
  success:  function(response) {
    # Cargar modal(response)
  },
  error: function(response) {

  }
});