Halloween props. Used them on a scare crow.
I transformed some plastic skulls I thought were boring into shrunken heads by cutting some locks frome an old wig.
You could make a couple of braids, tie them securely, cut them off, then affix them to your trunk in such a way that makes it appear someone is in there, or hang them from the behind side of your bumper.

Would an old wig be sanitary to put on someone else’s head? Aren’t you asking for trouble putting someone else’s lice and DNA on your own head?

Have you tried using a decent conditioner on them? I haven’t worn a wig in over 20 years, but that’s how I kept mine from tangling. Just every so often I washed and restyled them to help keep them looking more natural. Now if it’s a cheap Halloween wig, I’d throw it away and buy a new one. Wearing a ratty wig makes you look ratty, so buying a fresh wig will help to make you look better

I have a bag of about 30 wigs of various colors, lengths, etc…that I keep nice and bagged for special events, Halloween, etc…. At this point they can be cut or styled as needed with no distress. Generally I just keep them brushed out and folded/twisted nicely a few times a year, and they look fine.
(Uploaded a profile of Halloween last year. I cut this long dark wig to fit my Snow White costume needs.)

@elbanditoroso lice can’t live indefinitely. Only a few days without a host.
Worrying about DNA is just silly.

I’d use them for Halloween and give the rest to Goodwill.

Amend that. I google. Lice can only live for 1 day without a host.

Donate them to your local high school or other acting/stage group.

I never imagined that wigs might wear out. Tangling and shredding? Can’t they just be brushed and styled like real hair? I guess you have to deal with split ends, and the fact that real hair is constantly renewing itself, but how durable is a wig? Is there some wear index like there is for tires when it comes to quality?

They’re probably 50 years old @stanleybmanly.

Wigs come in various types and quality. The ones made with real hair would be a big variety.
Also, how they are manufactured has a bit to do with how long they stay nice.
I like the idea @kritiper has. Some schools these days have high aspirations for their theater students, but mighty low budgets.

I would wash it good and give it to kids to play with or the drama department of a school.