I'm fairly new to pinball troubleshooting so I am hoping someone can point me in the right direction. I've got a Gottlieb Haunted House and an entire segment of playfield lights fails to illuminate and stay on about half of the time. Sometimes it lights, other times it just flashes and fails to stay on. During attract mode, the normal behavior is for alternative segments of lights to toggle on/off, back and forth. You can hear the switch alternate the lights but every so often the segment just flashes rather than stays on. I've attached a link to a video showing the issue. (please forgive my use of the word 'clicker'; I really mean 'switch')

Thanks! That was the direction I needed. I haven't messed with those relays before but I sanded the contacts, put some deoxit on them and tweaked them with an adjustment tool and it seems to be better (after several hours of fine tuning). thanks!