This is a quick and easy project with just a few ingredients. A battery powered light up firefly made from a vintage sprinkler hose attachment.

Supplies

Vintage sprinkler attachment
Christmas bulb (yellow works best)
Melon ball scooper
Fairy lights ( you can get these at Amazon in packs of 12 for about $1 each)
Round top screw
Glue
Cork
Toilet Chain
Alcohol Ink ( optional)

Step 1: Collect Materials

These are the main ingredients

Step 2: Clean and Sand the Sprinkler

I used a sanding attachment on the angle grinder to sand off most of the rust ( not all ) so I had some raw metal which I'll later be adding a little color to. This is optional. Leaving it rusty is cool too!

Step 3: Make the Head

First cut off the scoops from the melon baller leaving enough of the 'stem' for a little nose? beak ? I used the grinder cut-off wheel, but you could use a hacksaw or dremel.

Then grind down the stem to a point. I used the bench grinder.

Step 4: Feed the Fairy Lights Through the Sprinkler

The sprinkler already has a hole in the middle of the bottom but you may need to drill it out so that it goes all the way through the cylinder.
Next, feed the fairly lights through the bottom hole and out through the back of the cylinder. Tweezers or small needlenose pliers can help you grab the string to get started.

Step 5: Cut Off the Bottom of the Bulb

I used a dremel cut-off wheel to gently cut off the bottom of the bulb to take the filament out. I also used a little grinder attachment to open up the hole a bit.

Step 6: Stuff the Bulb With Fairly Lights

That's it, just stuff the bulb with the string of lights. They are very bendy and even though the string is long, they will all fit in the small bulb.
This is good time to test the lights to make sure they work, before everything is glued in place. I've found some of the strings have bad batteries, etc.

Step 7: Glue the Bulb in Place

I used a little E6000 inside the rim of the sprinkler to hold the bulb in place. At this point I also "colored" the battery pack black with a sharpie because I didn't like the look of a white plastic battery pack. If black it's kind of hidden.
Don't use paint or you run the risk of damaging the batteries, connection or sticking the case together and you won't be able to change batteries.

Step 8: Attach the Head

Drill a hole in an appropriate sized cork. It can stick out a bit because the melon ball scoop is a little bigger than the opening and hollow. Put the cork in the sprinkler end, cover with the scoop head and screw in the round head bolt. The melon scoop should already have a hole in it.
The round head of the bolt should fit the shape of the round scoop and be flush.

Step 9: Attach the Battery Pack to the Body

I used super sticky, clear mounting tape to attach the battery pack to the body on the bottom of the cylinder. It's removable and restickable which can make it easier to change the batteries if you need to.

Step 10: Add a Hanging Chain

I used a length of old toilet chain and attached it through the existing holes in the "wings". I secured the chain with two small pieces of wire and tacked down with Gorilla super glue. It's very secure but can easily be chipped free if you decide you need a longer or different chain later.

Step 11: Final Touches

I used some alcohol inks in yellow, blue and green to give the raw metal on top a more insect-like sheen. Alcohol inks are great, you just squeeze a few drops on and let them mix and spread on the surface to 'stain' the metal. it will dry in a few minutes.