As a hobbyist, I didn't end up working on too many TV's and when I did, I looked at everything inside as wanting to kill me. Reading the Serviceman column in EA gave me a lot of good information - especially of the things that could go wrong ... and the one hand in the pocket rule.
There was, however, one time when I was building the Playmaster 132 project out of EA. My father worked in the office of an engineering business that had all the metal fabrication gear you could wish for, so I was able to get the chassis made up as a 'foreign order'. I was also able to get a front panel cut (made from food grade stainless steel) to which I added Letraset, giving a fantastic result.
During the final stages of the build, I had the unit plugged in and picked it up by the chassis to turn it over when I felt this sharp pain in my fingertip that felt (as I might imagine) like a huge spider had dug its fangs into me. There was no other discomfort. I quickly put the chassis down and inspected my fingertip to see two little black marks. Yep - they were burns. So I unplugged the unit and sat back for a few minutes contemplating what had happened and wondering how, until I gained the confidence to approach the unit again.
The answer was very obvious when I check the AC power switch. When I had wrapped my hand around the chassis, the affected fingertip had gone underneath and made contact with the exposed switch contacts. The 240v then travelled less than 1 cm to the chassis which was securely earthed, saving me from a worse fate.
Ever since then, I have had a healthy respect for one fundamental construction technique - when you have your mains wiring secured, tested and ready to rock - WRAP IT UP.