Is your paranormal group interested in exploring Horsham's most haunted house?  We can arrange an investigation of the Keith House at Graeme Park for you. $40/person. Five person minimum - 20 person maximum. 7 pm to 11 pm on  a mutually agreeable date. Please email ghosts@graemepark.org for information or to make arrangements.   Private Paranormal Birthday Party Celebrate your birthday with the ghosts as you and your guests explore Horsham's most haunted house with our investigators. $45/person includes a birthday…