Two things cross my mind : when I went away my lights were on a timer, as well as the radio. My neighbour had a key and opened and closed the curtains and re set the burglar alarm, plus taking any parcels, etc home with her (must add likewise, I looked after her two dogs when she was on hols, although this involved a 5.00am walk before I went to work, then her mother came and too over the dogs.....I walked them and had them in my house overnight when I got home from work ! I also just stayed in the house of a friend (young couple, very hi tech !) the tv came on, lights and the coffee machine, the blinds opened at sunrise and closed at sunset automatically ! even the front door had a remote lock he could open from his phone !! ha ha ...I put a light on manually one night and couldn't turn it off …..ha ha...their neighbour went past dog walking at 4.00am and said the next morning he was concerned the bedroom light was on and was I ok (fortunately he didn't knock at 4.00am !!)….talk about confusing the old ha ha …..I was glad to get back to my low tech house that doesn't speak to me !!!
Take it in, or if you are really of a mind, send it back to the address from whence it came …………….or go and put it on their doorstep from whence it may disappear ………...wait until the normal time they are due home !! good luck