So the light in my kitchen, which can be controlled by two different switches, is not turning off. If I flick the switch enough times, it will turn off but this is not normal. The condo is three years old and this has just started to happen. What is the problem and how can I fix it?

Sounds like simply a bad switch to me.

Jamlotus - Yes he is right, you have some bad light switches and they need to be changed. If you intend on doing the change ,then make sure you have the circuit in the electrical panel breaker turned off while changing the switches, IM thinking from what you stated that you have (# WAY ) switchesIF YOU DO < GET YOU A PIECE OF PAPER AND DRAW THE BACK OF THE SWITCH ON PAPER <WITH SCREWS FOR WIRES AND DRAW WIRES FROM THE SCREWS AND PUT THEIR COLOR S ON EACH ONE < USE THIS FOR REKOOKING THE WIRES BACK TO EACH SWITCH> THE THREE WAY DOES NOT HOOK UP AS A REG> SWITCH DOES > IF THEY ARE 3 WAY YOU WILL HAVE 4 WIRES<TO EACH SWITCH !-RED:: !-Black;;;; ! White ::- 1 COPPER NO INSULATion. Ground:: I HOPE I HAVE HELPED <IF I HAVE <RATE MY ANSWER BELOW::: GOOD LUCK& GOD BLESS ( STAY SAFE) ::: F.B.E.:) ;) :D

Special attention to what color wire is on the Dark screw of the 3 ways.

So the light in my kitchen, which can be controlled by two different switches, is not turning off. If I flick the switch enough times, it will turn off but this is not normal. The condo is three years old and this has just started to happen. What is the problem and how can I fix it?
At your suggestions, I got a new switch. It turns out that it is a 3-way switch and so I replaced the switch that seemed to be the problem one. I hooked up the new switch, ensuring that the common wire went to the appropriate screw, etc. When I turned the power back on, it didn't work but the other switch does work. I tried switching some of the wires around but nothing seemed to work. Did I hook it up wrong? Any suggestions as to what I can do next?

Identify wires, and remove the 2 3 way switches. Of those 6 wires, one will be hot, connect to dark screw, at that same switch connect 2 remaining wires to either screw. Then go to other switch location, look for a hot wire, This will be one traveller, flip other switch, now see what other wire is now hot, this is your other traveller, the wire left over goes to your light and will go to common dark screw, the 2 travellers go to same colored screws on second switch.
Good Luck.

I suggest checking the contacts on the switches before replacing them. Check for bad contacts, wear.. miss tightened screws.. broken switches etc.