I was reading up on the life expectancy of different building materials when I came across this gem.

Screenshot is of page 122 portseattle.org/…/SEA-SIPP Technical Report Appen…

I guess the ethernet cables could last that long, but they rate house wiring to a lower lifetime. Ethernet cables are not “wireless”, however.

The only other wireless systems I can think of are garage door openers, but they are definitely not expected to last 50 years.