Alcohol CAN cause sleepwalking.
More Info: Though alcohol is not an underlying cause of sleepwalking, it can trigger sleepwalking in those who experience the sleep disorder.
A Little More about Sleepwalking
Somnambulism, the medical term for sleepwalking, is a series of activities acted out while in a deep state of sleep. It is more common than most people realize. There does seem to be a genetic correlation. A child who has at least one parent who sleepwalks is at risk of having this problem.  Estimates vary on the subject, but up to 15 percent of the population has the tendency to get out of bed at night while still asleep.  Certain factors can trigger a sleepwalking incident. Alcohol intoxication is one of them. 
How Alcohol Affects the Brain
It is the ethanol in an alcoholic beverage that brings on that feeling of euphoria. Once metabolized, the ethanol alters the level of neurotransmitters in the brain. Neurotransmitters are chemicals in the brain that carry information throughout the body. They contribute to motor control, muscle control, and a sense of pain.  They also affect mood, concentration, and sleep. Alcohol consumption can deplete neurotransmitter levels, which cause adverse reactions when not in balance including how well you sleep. 
How Alcohol Affects Sleep
Though 67% of those that suffer from insomnia rate alcohol consumption as an effective sleep aid, medically the reverse is true. The effects of alcohol may induce sleep more quickly for some, but its adverse effects quickly kick in. Alcohol reduces the length of time that a person enters the REM phase of sleep, which is imperative for normal brain development, learning, and mental skills. Alcohol in the system causes shallow sleep and frequent awakenings associated with vivid dreams, sweating, and general activation. 
Does Alcohol Cause Sleepwalking?
Alcohol is an issue for those who sleepwalk. It may trigger an episode, but there is little evidence to support the conclusion that alcohol is a direct cause of this behavior. Stress, an irregular sleep schedule, insomnia, and drug therapy may contribute the problem, as well. Adults who start sleep walking when they have no history of this problem should see a doctor to rule out an organic cause. If you tend to roam around when you are sleeping, avoiding alcohol may help. 
 Neurology, A.K. Licis, MD
Novel genetic findings in an extended family pedigree with sleepwalking
January 2011, Volume: 78, No: 1, pages 49-52
 Columbia University: Go Ask Alice
Sleepwalking Associated with Drinking
 National Institutes of Health
Sleepwalking: Causes, Incidence, and Risk Factors
What Are Neurotransmitters?
 McGill University
The Brain from Top to Bottom: Neurotransmitters
What Are the Effects of Alcohol on Sleep?
Sleepwalking Causes, Symptoms, and Treatments
Glossary of Terms
Euphoria: extreme happiness, sometimes more than is reasonable in a particular situation.
Genetics: a branch of biology that deals with the heredity and variation of organisms.
Neurotransmitter: a chemical substance which is released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse or junction, effects the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure.
REM: the portion of sleep when there are rapid eye movements (REMs)
Somnambulism: the medical term for sleepwalking a disorder that occurs when people walk or do another activity while they are still asleep.
“As sleep deprivation often contributes to sleepwalking, increasing the amount of time scheduled for sleep can be helpful. Other possible triggers for sleepwalking include alcohol and certain medications. Also, experts recommend establishing a regular, relaxing routine prior to bedtime to cope with sleepwalking.”
Sleepwalking: Coping Sleepfoundation.org