Alternative to Honeywell BDR91 (RF switching unit)

[Steveh2]

I'm looking for an alternative to a BDR91, or finding a unit capable of signalling one.

I want to be able to detect 230v in the house and then send a switching signal to an external unit approx 4 meters away to close a contact.
As I understand it, BDR91 can only be paired with other Honeywell controllers.

[sandyman]

I've used lightwaverf relays for a couple of things, they may help?
TBH your explanation is a little lacking on detail, can you be a bit more specific? diagram?