Excrement and razor blades have been sent through the post to Welsh politicians, research has found.
A total of 121 Welsh politicians told the Electoral Reform Society (ERS) they have suffered abuse.
It sent a survey asking every Welsh Assembly member, Welsh MP, MEP and councillor for their experiences of harassment.
The society said some examples were "genuinely shocking, disturbing and criminal".
The ERS said harassment and abuse were among the barriers putting people off entering politics.
A total of 266 politicians responded to the ERS survey, including 224 councillors, 26 AMs, 11 MPs and one MEP.
Of them, 40 respondents said they had suffered abuse online and one AM said she had suffered racist abuse.
One politician told the survey they were sent excrement through the post "in a (very tacky) Valentine's card".
Bethan Sayed, a Plaid Cymru AM, said she had experienced racial attacks since her marriage to Cardiff International Film Festival founder Rahil Sayed, who is from India.
She told BBC Radio Wales she had been sworn at and had comments about her appearance and racist abuse about her name and wedding dress on social media.
"I haven't really ever experienced those things, because I've got the most [Welsh name], Bethan Jenkins, I come from the south Wales valleys, and you've never had to face those sort of racist comments before," she said.
"I can't even imagine what people from BME backgrounds are having to go through in their every day lives if that's what I get within two or three months of getting married."
She said people needed to be educated more about what politicians actually do, as she said part of the tension stemmed from people feeling frustrated at things not changing fast enough.
"People say to me 'well just put up with it', and 'get on with it', but should we really have to," she said.
Two politicians talked about suffering sexual harassment while undertaking elected duty.
One said they received "inappropriate sexual advances by constituents during advice surgeries and during door-to-door canvassing sessions".
Another recounted that they were once "slapped on the bottom", and that someone had attempted to pull them under a tree and kiss them.
One respondent told the survey: "When I worked for politicians I had access to their social media, answered the phone on their behalf and opened their correspondence.
"I opened an envelope with razor blades stuck to the inside."
The respondent added that a rock and a traffic cone were thrown at the politician's shop-front office window, "shattering the glass all over my colleague".
They added that a constituent had stalked them to their home.
"I have been a councillor for 14 years, I've won four elections and I've never had so much hassle or dissent as I have had in the last two years," Debbie Wilcox, leader of Newport council, said in evidence to the ERS.
Jess Blair, director ERS Cymru, said Welsh political parties should develop a joint code of conduct on intimidating behaviour.
She said: "If you look at politics from the outside, if you are a normal person sitting at home thinking 'I could do that' and you think whether you want to be trolled on social media or whether you want to be away from your family half the week, whether you want to travel huge distances; those things are a massive barrier - more than actually standing for a political party.
"The realities of public life need to be addressed."