Is this sketchy homemade extension cord with a wall outlet a fire hazard?

You aren't overreacting at all; that thing is a geniune fire hazard and a shock waiting to happen. The biggest issue isn't even the missing ground, though that’s bad enugh with a metal plug housing. It’s the fact that lamp cord—usally 18 or 16 gauge zip cord—isn't rated for the kind of physical abuse a workbench cord sees. The insulation on those thin wires is brittle and meant for a stationary lamp, not for being dragged across a shop floor or powering heavy inductive loads like a fan motor.

Using electrical tape as a substitute for a junction box is asking for a disaster. Over time, the adhesive in that tape dries out or gets gummy from the heat of the garage, and it will eventually slide or peel. Once those screw terminals on the side of the duplex outlet are exposed, all it takes is one accidental bump against a metal tool or a damp hand to cause a short. Plus, those terminals aren't meant to be under tension without a real **strain relief** system that a proper box provides. And since it's a two-wire cord, there is zero protection if a fault occurs. If a hot wire touches that metal plug housing beacuse of a loose screw or a frayed wire, the whole exterior of the plug becomes live. If your uncle touches that while standing on a concrete garage floor, he's the one completing the circuit. It's the kind of setup that works fine for twenty years and then kills someone in twenty seconds.

I'd honestly just snip it into pieces and throw it in the trash bin so he can't fish it back out. You can buy a 25-foot **14/3 extension cord** for cheap at any hardware store. It’ll be safely grounded and properly insulated for a shop enviroment. It’s not about being over-cautious; it's about the fact that the failure mode for this specific DIY job is usually a structure fire. Old-timers love to say "it's worked for years," but luck isn't a safety strategy.

That part about the tape adhesive drying out makes so much sense. I’ve seen old tape turn into that gross sticky goo in my basement, and I can totally see it just sliding right off those terminals. I didn't even realize the plug housing being metal was such a big deal until you mentioned it—that sounds terrifying if it actually goes live. If I head to the store to get him a replacement, shold I look for a specific gauge for shop tools? I see 12/3 and 14/3 cords and I'm not sure if the thicker one is overkill for just a fan and some work lights.

Grab a 12/3 cord if you can find one on sale. It’s a bit beefier than 14-gauge, wich helps if he ever decides to plug in a circular saw or a space heater instead of just a fan. The thicker wire prevents voltage drop, which keeps his tool motors from burning out prematurely.

Also, keep an eye out for a cord labeled SJOOW. That oil-resistant rubber jacket stays flexible in a cold garage, unlike the cheap vinyl stuff that turns into a stiff, coiled mess the second the temperture drops. If he realy likes having multiple outlets at the end, look for a heavy-duty 'power block' style cord. It gives him the same utility as that DIY disaster but with actual strain relief and a grounded path.