Why does my well pump turn on when I haven't used any water

Hi anduas and welcome, you must have a leak somewhere. Turn the water off going to the house and tell us if the pump kick on.

Also, what kind of pump? And plumbing will help get the best answer, OK?

PT is right. One place to look is a leaking flapper valve in a toilet.

Let's check a little farther. Shut the pump off and close the stop leading to the house. Now watch the gag. If it drops then you either have a faulty foot/check valve or a leak in the suction line What type of pump system do you have? If it holds steady now close off the house stop and open up the line from the pump to the house. If the gage still holds open the house stop. If it drops in pressure then the leak is in your house and you can check the toilet flapper. Let me know what you find. Good luck, Tom

I have a Myers submersible pump (I believe it is about 150 ft down) Have a Wellxtrol model wx202 in house. Gag is set at 60# shut off and 35# when pump kicks in.

AN, Speedball and Parttime gave you good advice. Follow that and let us know what you find out.

With a submersible pump we can rule out a faulty foot/.check valve. But still try to localize the leak. Good luck and let us know what you find. Tom