Dome Flashes and woman's voice speaks

I've got a wired camera w/ floodlights. Purchased several years ago. It's wired in place of one of two garage carriage lights. I turn it on, from the garage light switch, generally only when I leave my house and at night. It's generally been problem free. In the last week or so when I've turned it on at night the white plastic dome beneath the camera flashes (not strobes) and a woman's voice says something from the camera's speaker. Being hard of hearing I cannot understand what "she" says. The message is said only once and the dome continues to flash. If I turn off the camera from the switch and then turn it back on the camera/floodlight behaves normally. It doesn't happen every time I turn on the light switch. It's only happened about 4 or 5 times since it started about a week and a half ago. Since it doesn't happen every time, and the "woman's" message isn't repeated, I don't know what I'm missing. I don't know if it's some kind of error message, an advertisement or a warning. Would someone please tell me what is happening and whether or not I need to address some issue? Thank you.