How is someone controlling my iPhone?

Your device cannot be controlled remotely. It is possible that your iCloud account was breached if you did not use a strong password and two-factor authentication. If you think your Apple ID has been compromised - Apple Support

It's still unlikely as you would have video of someone either stopping recording or picking up the device. It is improbable that you have been "hacked." It's far more likely that your credentials were discovered. Change your password and enable 2-factor authentication. If you want a far more radical solution, reset your device to factory settings and then set it up as a new phone without recovering from a backup. You'll lose any data you haven't synced to iCloud.

Restore your iPhone to factory settings. Do not use a back up:

Restore your iPhone, iPad, or iPod to factory settings - Apple Support

For total peace of mind, you can create a new Apple ID and Apple ID Password for the iPhone. BUT and this is a big BUT, EVERY app you ever downloaded under the old ID will need to be repurchased under a new ID. Apps are forever tied to the Apple ID they were downloaded under.

At a minimum when you restore the iPhone and sign in with your current Apple ID to get back all your apps, CHANGE YOUR ID PASSWORD.

This is how you to do that --> Change your Apple ID password - Apple Support

Courtneymurtaugh wrote:

Yes my phone has been left recording videos while I was away MANYYYY TIMES!

Capturing video? That’s a button on the lock screen. No hacking required.

As for the rest of this, you will want legal counsel or a discussion with local police, as what you are purporting has happened here can be considered a civil or criminal matter in many places, as potentially also grounds for divorce, and is less so a technical issue, particularly given your reported previous efforts toward remediations.

iPhone was hacked while it was charging. The phone suddenly lit up and dialed a 1800 number, then garbage digits showed on the display. I tried to wrestle the phone away from the remote operator but they were lightning fast. they went into my settings and changed the emergency off screen touch controls, then started rifling through my most recent photos and when I tapped all over the screen and kept wresting the phone controls away, the remote operator dug in my latest conversations and pulled the latest images. Major lightning fast hackjob. Reset my iCloud and apple passwords. Yall should do the same. this happened around 10.45pm pacific time, Jan 2, 2023.

That actually sounds like you have a bad charging cord. A bad charging cord can cause al sorts of really weird things, including the phone dialing and switching apps.

In order for your hardware to have been compromised, someone would have had to have had physical access to the phone. And, in that case, changing your iCloud password wouldn’t have made a whit of difference.

Courtneymurtaugh wrote:

My phone was left behind recording a few times giving anyone access to my phone.. which they would also be able to figure out my passwords to get in. If someone did have access to my phone what is it that they did to it for it to be controlled by another device & make everything I do or on my phone visible to them without iCloud showing another device?

MOST unlikely.

My phone was being remotely controlled by a hacker that took over my email accounts and social media accounts. My identity was stolen and my phone was being controlled by the hacker. I would get booted out, my lock folder was accessed and now gone. A picture of my baby I miscarried was set as my Lock Screen and wallpaper. So many things so I had it disconnected but friends and still getting texts from the old phone number.

This phone iPhone 12 is new and it is extremely hot and one day I went to make a call. The number was disconnected but it was a business and from being hacked I was told to call that number if anything happens. I checked my scribbler, I have to write everything down and the number for the person was changed. It wasn’t even remotely close to the actual number.

Looking forward to seeing what others have to say or offer ideas for more security though I have done a lot to secure this phone.

You just keep repeating a completely implausible story over and over and over, with the hopes someone is going to agree with you. It is virtually impossible to remotely control an iPhone. Repeating the story multiple times isn't going to change anything.

Do the things we've recommended and move on with your life.

When did you hand your phone over to someone to let them use it without your consent or to monitor them? If you haven't, no one can control your phone.