not necessary. just find a nice cool dark place in your house. a basement, closet, darker corner of a room works fine. as long as your homes temp doesn't constantly fluctuate 10 or more degree up and down you don't require a wine fridge.
my neighbors a sommelier and owns a wine store. he has a wine fridge but to only keep his whites in that he likes to keep on hand and not taking up his actual fridges space.
also unless you plan on spending big bucks on wine or collecting vintage wines your also not going to need it. most wines don't require multiple years of storage anymore like they used to.
retired 06 E90 325i
New: 09 VW Platinum Grey Jetta Sportwagen 2.0T SEL w/DSG, panoramic sunroof and Ipod adapter