Autism Wairarapa Charitable Trust field worker Wendy Roesler showed up to work on Friday to find her desk covered in broken glass - and a road cone in the middle of the room.
Ms Roesler's Queen St office was one of several Masterton CBD businesses vandalised last week, and two where the perpetrators have left a traffic cone as a calling card.
Masterton police were called to the charitable trust's building and Kevin B Wong's dental practice on Renall St on Friday morning after staff reported broken windows, and appealed to the public for more information.
A spokesperson from Masterton District Council mentioned a window had been broken at the Masterton Town Hall on Thursday night, but this was not reported to police.
Ms Roesler said she received a call before work from a neighbouring shop, her trust's office window "had been smashed".
"My first thought was 'someone's trashed the place'", she said.
"Pretty much everything we've got has been donated, and we do not have the funds to replace it.
"I got in, and there was broken glass all over my desk." She said the office's side window was broken - possibly by someone throwing the road cone through it - and the security seal on the back window was also damaged.
The glass was repaired soon afterwards - but the damage has been done for Ms Roesler and her colleagues, who found the incident "really upsetting." "Come on, guys - we're a charity.
"We work for nothing, and we rely heavily on the generosity of the public.
"It's probably some moronic idiots with nothing to do - but why they'd target a non-profit organisation seems senseless to me.
"It's disheartening."
Dental practice owners Kevin and Vivien Wong discovered two smashed windows and cracked glass panels in their front door.
A road cone was also found inside.
Practice manager Mrs Wong said repairing the damage was costly.
"The insurance covered it, but it was a $500 excess - so we woke up $500 short that morning," she said.
"It was quite bad." Mrs Wong said this is not the first time the practice has been vandalised.
"It usually happens about three times a year.
"I think it might be drunk people." Masterton police senior sergeant Mike Sutton said police are investigating the matter, starting with a review of CCTV footage from Thursday night.
"It looks like a pretty random attack - but we're keeping an eye out to make sure this doesn't become a pattern."
Mr Sutton encouraged any other business whose premises had been vandalised to contact police.