Have any of you had spooky experiences with baby monitors?

when i was babysitting for this woman, i barely ever used the monitors but i went and layed down her baby and i turned on the monitor. when i went back to the living room i watched television, and like 5-10 minutes later i heard a man talking queitly on it, which scared the crap out of me! i was so scared to go back to the room , but i knew i had to because i wouldnt let anything happen to the little baby. so i turned on all of the lights and walked slowly back there with like a bat or something in my hand! when i got there nothing, so i looked in the closet, made sure the window was locked and went back out there, and still there was someone talking. then i realized that there was a woman too, and thats when i figured out it was someones phone conversation, still to this day i get scared when i hear noises or talking on my daughters monitor, hers makes wierd noises, noone talking though, just creepy noises..