A sound is ringing

My home's smoke detector started making a noise around 3 AM, saying "Fire! Fire! Whoooooosh!" and it wouldn't stop, which was a real problem. It wasn't actually a fire, and I hadn't been cooking or smoking, so there was no smoke. I thought it must be broken, so I took out the batteries and left it. But just as I was starting to doze off, it went off one more time and woke me up. I thought, "You darn thing!" 💢 The next day, I had a friend who works at an electronics store take a look, and they said, "It's probably not broken anywhere." They even added, "If you removed the batteries, there's no way it would make a sound. It's impossible for residual electricity or anything." My friend and I both turned pale. Anyway, they put the batteries back in and gave it back to me. I went home and put it back in its original spot. Around 11 PM that same day. It started ringing again. Even though I said, "This is too scary!!" and took out the batteries, the sound just wouldn't stop. My partner was working the night shift and I couldn't reach them, so I called a friend who had quit their black company job and was enjoying being a NEET, even though I knew it would be a bother. The sound stopped when I called. Just as I was feeling relieved, my friend who answered the phone said, "...? Huh? Is that a weird noise coming from your end? Like a brazier, you know. It's crackling, what is that? Are you okay?" At that point, I knew I was done for 🫠 and ran out of my house to the convenience store. That's the memory.