That's what has happened to a friend of mine, they tried to sell but couldn't find a buyer at a "reasonable" price (even after dropping it a couple of times) so they have decided to rent it out instead.
These houses that failed to sell might be what's behind the increase in rental stock, which is disturbing when the no. of houses for sale are already high in addition to this.
If that trend continues then the rental market will be oversupplied as well and rents will have to go down...
Prices down, rents down, interest rates up, spending down with businesses struggling -> jobcuts... The perfect cocktail?