Where to find a personal tracking device for my loved one?

Besides checking the local county offices, you can try a device I used call the 5 start tracking device. Go to greatcall. It is a gps device that one wears either as a pendant or wristband. It needs to be recharged every few days. It comes in a waterproof version also. You can then go online and track where the device is and what the battery status is. Costs about $20 per month for the monitoring svc, which includes a button to call in case of emergency.
The trick is to have the patient wear it at all times. I sold it as a call button for help, which it is.. At the later stages of course, he wouldn't remember how to use it.
Good luck!

I was having issues with where to put a device on mom because they were all too big and noticeable. But then mom wandered off on one of the aides and luckily we found her not to far away from the house within 20 minutes. But that started the process and I discovered that thru the county they had a beta tracking system in place. For mom, because my dad was a veteran, the VA pays for the month cost of the tracking device which is an anklet so it's less disruptive to mom. I haven't had to call, but it's comforting to know that I can. I would check with your local police department, that's how I found this little gem. Good Luck. Take care of yourself.

Here's an idea I'm using. It's not typical, but it's less expensive than 24/7 monitoring for those not needing every moment captured ($20 on sale) and it works up to a mile using bluetooth. It is called THETILEAPP and you get a tile to attach to SOMETHING on your loved one. I put a TILE on my Mom's dog leash (she wanders with his companionship). I can see where they are by turning on my Bluetooth and get the car to go get them. It wasn't designed for caregiving purposes, but in my case, it's just as valuable as a life alert, and less intimidating (so she hasn't ripped it off like most devices "I'm not that bad yet" she says, and most days she's right). But one day she got lost in the rain with the dog, THE TILE alerted me and I got them home. Good luck with your heavy-hearted decision. It's not easy for most seniors to be tracked willingly. I told Mom what it was for and she still has it! It needs to be replaced once a year, so I guess it will be costly if I'm blessed with 30 more years of this ;). 
I also have a tile on my car keys!  It WAS designed to help find keys!  

Before you buy check with your local Sheriff's Dept or Police Dept. to see if there is a program in place to help with locating a stray wandering person. Our county has a program set up that the individual wais fitted with a tracking bracelet and it is checked by one of their community service personnel monthly to make sure it is working properly. My husband was fitted with one and luckily we never had to call them but just knowing that they were available should they needed to be called was comforting. The program in our county was totally free and funded by contributions from the community.

It depends your situation. MIL never leaves her home so I use a Nest audio/video surveillance system. The whole set up was about 500.00 but you need to have wifi in the home. The cameras just plug into any outlet and the wires it comes with are very long.
I can talk to her and she can talk to me hands free. I get movement and noise alerts to my cell...it's great!!