I recently picked up a project Bally Speakeasy and have been cleaning it up / LED conversion etc. I kept thinking that I was getting shocked by the lockdown bar brace when the game was plugged in but not really bad. Note I typically don't wear shoes in the basement and the work area is not carpeted. I didn't feel anything when the lockdown bar was installed and playing the game.
Today I dug out the volt meter and measured from the right side rail to the brace (with glass and lockbar off)...... hmm 12.9vac..... I took apart the replacement plug that had been installed at some point in this games life to find this..... there are 3 wires in the cord for a reason people....after fixing the cord and testing again the stray voltage is gone. I plan on checking the in cabinet ground wire connections later to make sure they are all solid as well.