I'm curious what sort of cautionary tales everyone has come across (or experienced themselves).

For instance, my dad used to work on live wires all the time — until he was putting a stove in (220V if you don't know) and touched two wires together. The spark flew off and hit his glasses and melted about halfway through the lens. He still works on live 110V, but he always turns off the 220 circuit now.

What about you? Any (hopefully just-as-happy) shocking experiences you folks have had?

  • 3
    I melted the tip off a screwdriver doing a similar operation on my outdoor AC unit. I think you need that to happen once or twice to teach you to respect electricity and not get complacent.
    – JohnFx
    Jul 23, 2010 at 21:48
  • That reminds me of someone who tried to see if the cable he bought would plug into the outlet. He ended up knocking out power to the whole block. Jul 24, 2010 at 1:06
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    Capacitors can hold deadly amounts of electricity. Since talking to a few HVAC repairmen, I try to keep one hand in my pocket. Discharging a capacitor across my heart is not something I want to do (or any other part of my body, but the heart least of all). Jul 24, 2010 at 5:00
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    @Brad, if they managed to do that I'd be seriously concerned about the level of fusing your electricity provider has put in place! Jul 27, 2010 at 5:10
  • Was just talking with a general contractor the other day about how every year he hears of a few HVAC guys dying from electrical discharge on AC units, so definitely one to be very mindful of.
    – ManiacZX
    Jul 28, 2010 at 12:02

8 Answers 8


I once had a tenant who lived next door in our duplex and thought she could hook up her own gas drier. Smelled gas one day and couldn't find where it was coming from, so I knocked on her door. Walked in and the whole place reeked of gas.

Checked the drier, and sure enough, the supply line was barely even screwed on. Asked her about it and got one of those "Yeah, it's been like that for a while now, was going to ask you about that" kind of responses. Lucky it didn't take out the whole neighborhood.

  • They make a little device you can screw on to the end of the gas line coming from the wall, which will close if the gas comes out uncontrolled. Depending on the amount of gas escaping, that may or may not have helped here.
    – Jay Bazuzi
    Nov 11, 2010 at 3:33
  • let me guess: she didn't use black thread sealant?
    – amphibient
    Dec 31, 2013 at 16:54

Treat your router like a loaded gun, it has a ton of power and can shoot things with a lot of force if you aren't using it correctly.

Consider that a router runs at around 24,000 rpm

compare that to...
A table saw: ~4,000 RPM
A drill: ~800 RPM

The feed direction and double checking that the bit is securely locked into the chuck is critical if you value your life and/or limbs. If it is making a funny noise, stop immediately and check it, even if it is a pain in the butt.

Just once, I shot a loose bit across my workshop at terrifying speeds. I always check thrice since that day.

  • 4
    Angle grinders are in a similar boat. Jul 25, 2010 at 3:30

Well, I had one that more so lead to a DIY project then happened during.

Commercial building built in the 1930s, had lamps hanging from ceiling by chains.

One day I'm changing a light bulb and someone walks in and flips the light switch.

It threw my arm back, almost knocked me off the ladder, and my hand was spotted black for a little while.

The wiring running through the chain to the lamp was cloth insulated and had broken down over the years. Needless to say, I spent the rest of the day rewiring all of the lamps in the building.

So, be mindful of working in old buildings, even on the simplest of tasks.

  • 1
    Tape across the switch can be a nice reminder to not turn it on...
    – derobert
    Jul 29, 2010 at 21:43
  • I was just changing a light bulb, aside from sticking my finger in the socket, I had no expectation of electrical shock. When I did the rewiring, I pulled the fuses (yes, fuses, not circuit breakers).
    – ManiacZX
    Jul 30, 2010 at 0:13
  • I always try to isolate the supply when changing a bulb, ever since one of my friends was thrown off a chair by a shock he got when the bulb he was putting in broke in his hand. Nov 23, 2010 at 18:02

If you're doing a job that creates a lot of dust, it's really worth tarping off the doorways to limit exposure. After doing a floor sanding project, for the next few months my laser printer smelt like a fireplace every time I printed something.


Be careful when walking/working in your unfinished attic... it is very easy to miss a beam and put your foot through the ceiling. Best thing to do is use a piece of plywood if you need to work up there for any extended period of time.

  • My dad almost came through ours (we have some plywood) - he said the easter bunny pushed him (he was getting our easter decorations). I almost did getting an aquarium out of the attic. Then just recently my sister did as they were cleaning it up. You think we'd learn a little better, eh? Jul 24, 2010 at 4:52
  • just out of curiosity, why don't builders put down plywood decks across those joists? Seems like it wouldn't be that costly and makes the attic much more safe to get around in.
    – JohnFx
    Jul 24, 2010 at 15:11
  • 1
    @JohnFx: Sometimes attic insulation is piled in there higher than the 2x4 joists, so you'd lose insulation by putting plywood decks everywhere.
    – Doresoom
    Jul 24, 2010 at 18:37

Never leave wire ends unprotected, even for a moment. It's too easy to get distracted and forget to replace a wire cap or crimp a connector. And once the junction box (or wall!) is closed up, it's too late, and some day later you cause an electrical fire.

  • I was hacking out some damaged plaster and got a shock off a wire with unprotected ends buried in the wall. I think there must have been a light fitting there at some point; and whoever removed the light just covered the hole and the bare ends of the wire in filler. I now make far fewer assumptions about where I might not might not find wires. Nov 23, 2010 at 18:09

Always, always, always, always, always make sure the power is off before snipping 240V power cables. And when you do snip them, even if the power is off, make sure your hands are insulated.

We had an electrician swear to us that he had disabled all the power to one part of the building, but even so I felt a tingle so I went and confirmed with him that the power was off. He rolled his eyes and said yes. So I got my snips and cut through the wires. BANG! Lots of sparks and some very loud swear words. Thankfully I just happened by pure chance to have my hands insulated.

  • 6
    That's why I always check the cable with one of those contact-less voltage detectors. You can even buy screwdrivers, wire strippers, and multi-meters with that feature built-in. Jul 24, 2010 at 1:09
  • I did a similar thing with a little Gerber lock-back knife and 110v. I thought the lamp had a short in it so foolishly I thought "I'll just cut the wires and see if I can find the short"... That was exciting for a moment or two. Jul 24, 2010 at 4:53
  • 2
    If he was so darn sure he'd disabled them...why didn't he cut 'em? Jul 28, 2010 at 21:04

Most of my DIY experience and interest is in electrical matters, so the stories I have are from that.

The people who built a house I have improved did alot of things themselves to save money - which I don't look down on! What I DO is the way they did certain things. Probably the most annoying thing was to route a line through a switchbox that did not feed anything. Turning off all the power to the lights the switches fed was not enough to prevent a strange tingling feeling.

I will admit this was many years ago and I was less experienced and felt more invulnerable. I also admit that I should have questioned all the cables entering the box, since I then would have noted the odd one.

Another one that still gets me is people using a white (NEMA color code) coated wire as a hot line and not marking it. I've fixed that many times.

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