It happens!! In my case, I had a Hydor Koralia leaking stray voltage. There was also a pump on my Reef Octo skimmer that was suspect. I'm still jumpy and now I wear gloves - nice long ones if I have any real work to do. I will admit to getting occasionally lazy with food but I'm like 95% gloves - 100% slippers. If I change socks or work in the sump, I cut power. Honestly, I do a better job without flow throwing nasty stuff everywhere anyway so it's kind of a no brainer. Not shutting down is really lazy.From now on I am pulling the plug on anything. Got a jolt putting my hands in my tank once when the wire insulation was compromised on my power head
Stay safe.