Mystery Solved

The noises on Sunday night that Mom reported with agitation on Monday afternoon were real, but they were not her Posey alarm.
I went to Ocean View last night at 11 pm to find out what was happening, and it turned out to be her Motorola walkie-talkie.
First I checked on her and all was well, so I talked with the two caregivers on duty and reviewed various events in her care at night in the last ten days.
"Did anything happen last night? Is there anything written in the log book about her?" I asked.
"Sometimes there are things that I don't want to write down, that I need to discuss with you personally," Rose began.
I didn't get it until she said, "Masturbation."
After several months free of that problem, the behavior has turned up again in the last week, as Jona mentioned to me a few days ago. So Rose and I discussed it and the Posey alarm, and I went to check on Mom one last time before going back home.
When I walked into the room, the walkie-talkie on her bedside table was beeping and emitting short bursts of static, followed by a man's voice speaking.
So that's what the noise was. No wonder she was exasperated and hadn't been able to sleep last night, though she was sleeping deeply at this point.
Someone else was using the same radio frequency, Channel 1. It wasn't anyone on her floor of Ocean View, so I figured it could be anyone in the adjoining buildings.
It took me a while to find the instructions and figure out how to change the channel. I tried channel 3, and it seemed to be free of any other conversations, for the moment.
I gave a Valentine's bag of Hershey's kisses to the caregivers and went home, relieved that I had been able to find the problem and maybe even solve it.