C# Word Guessing Game

Question

I am trying to get this game to stop if the user guesses wrong 3 times. It is checking a random word character by character and updating if the guess matches any of the letters.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Hangman_2
{
class Program
{
static int wrongGuess, lettersLeft;
static void Main(string[] args)
{
string wordToGuess = GetWordToGuess();
char[] maskedWord = GetHiddenLetters(wordToGuess, '-');
lettersLeft = wordToGuess.Length;
char userGuess;
wrongGuess = 3;
while (wrongGuess > 0 && lettersLeft > 0)
{
DisplayCharacters(maskedWord);
Console.WriteLine("Enter a letter?");
userGuess = char.Parse(Console.ReadLine());
maskedWord = CheckGuess(userGuess, wordToGuess, maskedWord);
}
Console.WriteLine("Well done! Thanks for playing.");
Console.ReadLine();
}
static string GetWordToGuess()
{
Random number = new Random();
int wordNumber = number.Next(0, 9);
string[] words = { "hyperbaric", "temporal", "quantum", "radiation", "aardvark", "accident", "dracolich", "professional", "properties", "collections" };
string selectWord = words[wordNumber];
return selectWord;
}
static char[] GetHiddenLetters(string word, char mask)
{
char[] hidden = new char[word.Length];
for (int i = 0; i < word.Length; i++)
{
hidden[i] = mask;
}
return hidden;
}
static void DisplayCharacters(char[] characters)
{
foreach (char letter in characters)
{
Console.Write(letter);
}
Console.WriteLine();
}
static char[] CheckGuess(char letterToCheck, string word, char[] characters)
{
if (wrongGuess > 0)
{
for (int i = 0; i < word.Length; i++)
{
if (word[i] == letterToCheck)
{
characters[i] = word[i];
lettersLeft--;
}
}
}
else
{
wrongGuess--;
}
return characters;
}
}
}