My 1980s house has compressed straw dryling plaster boards for the upstairs internal walls.
When fitting sockets to one room I unexpectedly but conveniently found a cable channel running vertically in the panel.
Now I want to find one of these in another room - I'm guessing that the only way is to dig a horizontal channel until I find one (I've already decided where the pattress boxes will go so I'll need to cut a channel anyway), but how far apart are they (don't want to find I go a long way in one direction only to find that there is one the other way very close!
Any tips on finding the channel?