I can't recommend anything but I have to believe that something like that exists. I have garage door sensors that flash a red LED when one of the doors is open but the mechanism that actuates the LED requires the sensing mechanism to tilt from vertical to horizontal (it's mounted on the inside of the garage door).

There are so many inexpensive cordless DIY alarm systems now that you might be able to use parts from a basic system to make something that works for you.

Bob

i know how to do it for a wired system, just not for a wireless.

you take a basic wired system and hook a 12v light to the siren inplace of a speaker. you run a line to the window and put a window sensor there, and run another line to the door and put in a door sensor there. hook these up in parallel at the panel. if BOTH are open at the same time, the light comes on. either one opens and the other is closed, and no light. we actually did this at a few locations when i was installing alarms.

you can do the same thing with a DC wall wort and a relay and 2 sensors.