graphs and networks - How to get "text wrapping" for long text strings when using LayeredGraphPlot

I start with a list of occupation titles:

OccTitlerules = {"Carpenters" -> "Sheet Metal Workers", 
 "Cement Masons and Concrete Finishers" -> "Carpenters", 
 "Construction Laborers" -> "Helpers--Carpenters", 
 "Construction Managers" -> "Cost Estimators", 
 "Cost Estimators" -> "Construction Managers", 
 "Electricians" -> 
  "Heating, Air Conditioning, and Refrigeration Mechanics and 
Installers", 

 "Fence Erectors" -> 
  "Helpers--Brickmasons, Blockmasons, Stonemasons, and Tile and 
Marble Setters", 
 "First-Line Supervisors of Construction Trades and Extraction 
Workers" -> 
  "First-Line Supervisors of Mechanics, Installers, and Repairers", 
 "First-Line Supervisors of Mechanics, Installers, and Repairers" -> 
  "First-Line Supervisors of Construction Trades and Extraction 
Workers", 
 "Heating, Air Conditioning, and Refrigeration Mechanics and 

Installers" -> "Electricians", 
 "Helpers--Brickmasons, Blockmasons, Stonemasons, and Tile and Marble 
Setters" -> "Cement Masons and Concrete Finishers", 
 "Helpers--Carpenters" -> "Construction Laborers", 
 "Helpers--Electricians" -> "Helpers--Carpenters", 
 "Helpers--Pipelayers, Plumbers, Pipefitters, and Steamfitters" -> 
  "Construction Laborers", 
 "Insulation Workers, Mechanical" -> "Roofers", 
 "Plumbers, Pipefitters, and Steamfitters" -> "Electricians", 
 "Roofers" -> "Insulation Workers, Mechanical", 

 "Sheet Metal Workers" -> "Carpenters"};

Then I build the following Layered Graph Plot:

LayeredGraphPlot[OccTitlerules, Bottom, VertexLabeling -> True, 
 BaseStyle -> {FontSize -> 12}, ImageSize -> 2600, AspectRatio -> 1/2]

Notice that I have to use a large ImageSize value because; otherwise, some of the labels contained in the text boxes will overlap. Unfortunately; doing this makes the plot so large that I'm unable to print it in regular 8.5" X 11" paper.

I cannot abbreviate the job titles because they are specific are necessary.

My question is; is there a way to "wrap" the text so that the longest job titles are better disbursed inside their text boxes?

For example; the job title:

"Air Conditioning, and Refrigeration Mechanics and Installers"

with text wrapping applied to it becomes:

"Air Conditioning, and Refrigeration

Mechanics and Installers"

Thank you!