If you have time to research just one haunted location in Boston, start at the site of the old Cocoanut Grove fire.
On 28 November 1942, Boston’s fashionable Cocoanut Grove nightclub (and speakeasy) was the site of one of the deadliest nightclub fires in the United States. Nearly 500 people died in the fire.
Today, a plaque at 17 Piedmont Street–and a small, paved parking lot on a street corner–are all that remain to suggest the tragedy. It was the second-worst single-building fire in American history.
Even in broad daylight, EMF levels surge irregularly at the site. (The streetlights are gas; wiring is an unlikely cause of the EMF.)
Piedmont Street is in Boston’s Bay Village, just a few blocks from Boston Common and Boston’s Public Gardens, and not far from several popular theatre district hotels. Find the location at Google Maps.