Wireless door switches?

I’m planing adding some facilities to my old wires burgler alarm in my house - it has some PIRs mounted and they works well, BUT …

I want to add some ‘mount on the door frame and listen’ for an ‘open’ signal’ wireless switches that my my Arduino main system can listen to via ESP or so.

DO you have any experience with some CHEAP and easy to use ones - let me know ?