It is the large, final building on the right on Toupee Terrace. It has been described as "reddish".
After you free the guy that is on top of the building that has all those windows that shock you, he gives you the bow tie.
in mercury
It is the last building on Toupee Terrace. Its windows shock you if you try to climb them. But you can do it if you move carefully from window to window as the power goes on and off. You will need the Laser Pen from the first spy (at the docks) to free the second spy from the attic of this building. (see related questions)
He is in the building on Toupee Terrace that zaps you with its electrified windows. To rescue the second spy, jump up the windows while the power is off (it takes timing). At the top, use the Laser Pen from the first spy to cut open the bars.
in spy island
The electrified windows on the building on Toupee Terrace turn on and off at regular intervals. You can climb up the windows by jumping onto a window where the power is off, then to another "off" window before the power comes back on. You need the Laser Pen to rescue the second spy (in the attic). You get the pen when you rescue the first spy (at the docks). (see related question)
It is the Second Building on Main Street on Spy Island on poptropica.com.
The last building on the right on Toupee Terrace has electrified doors and windows. You can climb it to rescue the 2nd spy, who is locked in the attic. You will need the Laser pen from the 1st spy rescued (at the docks). To reach the roof, jump to each window in sequence when the power is off, then again to another window before it comes back on. (see related questions)
when you save the first spy at the docks he gives you a laser pen. When you get the laser pen you have to go the the brick building with the shock windows and climb to the top. When you get to the top there are bars covering a window so you have to click on it and the laser pen will show up. Then you hold down your mouse and drag the pen across the bars and you are in!
To rescue the second spy, avoid the electrified windows. To rescue the third spy, you will need to go up one building to the rooftops, then to the far left and back again. This requires the Grappling Bowtie from the second spy. (see the related question)
Find a way to get to the top of the building
Take the Laser pen and go to the electrified building on Toupee Terrace. Climb the windows by jumping when they turn off. Use the laser pen to cut the attic bars and save the 2nd spy.