You shouldn’t test a fire alarm by starting a house fire, but there’s a joke:
 
“They say you should test your fire alarm every month. That would cost a fortune in houses.”
 
The jocular one-line saying has been cited in print since 2012.
 
     
Google Books
5,000 Great One Liners
Compiled by Grant Tucker
London: Biteback Publishing
2012
Pg. ?:
They say you should test your fire alarms once a month. It’s cost me a fortune in houses.
 
Twitter
TheeonlyCraig
‏@theeonlycraig
”@funnyoneliners: The say you should test your fire alarm once a month. I try but it’s costing me a fortune in houses.”
7:25 AM - 28 Dec 2012
 
Twitter
sickipedia
‏@sickipediareal
The say you should test your fire alarm once a month. I try but it’s costing me a fortune in houses.
7:25 AM - 28 Dec 2012
 
Twitter
Alex
‏@Talking_Teddy
They say you should test your fire alarm every month. That would cost a fortune in houses.
2:31 PM - 11 Jan 2013
   
Twitter
Joe Jaffa
‏@joejaffa
The say you should test your fire alarm once a month. I did that for a while, but it cost me a fortune in houses and fire insurance
9:26 PM - 14 Aug 2013
 
Twitter
Francois du Toit
‏@francoisdtoit
The alarm people said I should test my fire alarm once a month. I try my best, but it’s starting to cost me a fortune in houses.
10:30 AM - 30 Aug 2013
 
Twitter
Rob Thompson
‏@sirchutney
BBC NEWS: Test your fire alarm once a month ...
I would, but it’ll cost me a fortune in houses.
1:23 PM - 25 Jan 2017
 
Reddit—Jokes
They say you should test your fire alarm once a month…
submitted January 25, 2017 by Gurencia
But it’s costing me a fortune in houses!
 
Twitter
LaffGaff
‏@LaffGaff
They say you should test your fire alarm at least once a month.
But it’s costing me a fortune in houses.
#funny #jokes
4:12 PM - 4 Feb 2017